Collect UMA statistics on which chrome://flags lead to chrome restart on ChromeOS.

chrome/browser/about_flags.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/about_flags.h"
 
 #include <iterator>
 #include <map>
 #include <set>
 #include <utility>
 
 #include "base/command_line.h"
 #include "base/memory/singleton.h"
+#include "base/metrics/sparse_histogram.h"
 #include "base/stl_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/values.h"
 #include "cc/base/switches.h"
 #include "chrome/browser/bookmarks/enhanced_bookmarks_features.h"
 #include "chrome/browser/flags_storage.h"
 #include "chrome/common/chrome_content_client.h"
 #include "chrome/common/chrome_switches.h"
 #include "components/autofill/core/common/autofill_switches.h"
@@ skipping 31 matching lines @@
 
 #if defined(ENABLE_APP_LIST)
 #include "ui/app_list/app_list_switches.h"
 #endif
 
 using base::UserMetricsAction;
 
 namespace about_flags {
 
 // Macros to simplify specifying the type.
-#define SINGLE_VALUE_TYPE_AND_VALUE(command_line_switch, switch_value) \
-    Experiment::SINGLE_VALUE, \
-    command_line_switch, switch_value, NULL, NULL, NULL, 0
-#define SINGLE_VALUE_TYPE(command_line_switch) \
-    SINGLE_VALUE_TYPE_AND_VALUE(command_line_switch, "")
-#define ENABLE_DISABLE_VALUE_TYPE_AND_VALUE(enable_switch, enable_value, \
-                                            disable_switch, disable_value) \
-    Experiment::ENABLE_DISABLE_VALUE, enable_switch, enable_value, \
-    disable_switch, disable_value, NULL, 3
-#define ENABLE_DISABLE_VALUE_TYPE(enable_switch, disable_switch) \
-    ENABLE_DISABLE_VALUE_TYPE_AND_VALUE(enable_switch, "", disable_switch, "")
-#define MULTI_VALUE_TYPE(choices) \
-    Experiment::MULTI_VALUE, NULL, NULL, NULL, NULL, choices, arraysize(choices)
+#define SINGLE_VALUE_TYPE_AND_VALUE(                                          \
+    command_line_switch, switch_value, switch_uma_id)                         \
+  Experiment::SINGLE_VALUE, command_line_switch, switch_value, switch_uma_id, \
+      NULL, NULL, 0, NULL, 0
+#define SINGLE_VALUE_TYPE(command_line_switch, switch_uma_id) \
+  SINGLE_VALUE_TYPE_AND_VALUE(command_line_switch, "", switch_uma_id)
+#define ENABLE_DISABLE_VALUE_TYPE_AND_VALUE(enable_switch,         \
+                                            enable_value,          \
+                                            enable_switch_uma_id,  \
+                                            disable_switch,        \
+                                            disable_value,         \
+                                            disable_switch_uma_id) \
+  Experiment::ENABLE_DISABLE_VALUE, enable_switch, enable_value,   \
+      enable_switch_uma_id, disable_switch, disable_value,         \
+      disable_switch_uma_id, NULL, 3
+#define ENABLE_DISABLE_VALUE_TYPE(enable_switch,            \
+                                  enable_switch_uma_id,     \
+                                  disable_switch,           \
+                                  disable_switch_uma_id)    \
+  ENABLE_DISABLE_VALUE_TYPE_AND_VALUE(enable_switch,        \
+                                      "",                   \
+                                      enable_switch_uma_id, \
+                                      disable_switch,       \
+                                      "",                   \
+                                      disable_switch_uma_id)
+#define MULTI_VALUE_TYPE(choices)                                 \
+  Experiment::MULTI_VALUE, NULL, NULL, 0, NULL, NULL, 0, choices, \
+      arraysize(choices)
 
 namespace {
 
 const unsigned kOsAll = kOsMac | kOsWin | kOsLinux | kOsCrOS | kOsAndroid;
 const unsigned kOsDesktop = kOsMac | kOsWin | kOsLinux | kOsCrOS;
 
 // Adds a |StringValue| to |list| for each platform where |bitmask| indicates
 // whether the experiment is available on that platform.
 void AddOsStrings(unsigned bitmask, base::ListValue* list) {
   struct {
@@ skipping 39 matching lines @@
                     GetSwitchString(chromeos::switches::kPolicySwitchesBegin));
   last = std::find(cmdline.argv().begin(), cmdline.argv().end(),
                    GetSwitchString(chromeos::switches::kPolicySwitchesEnd));
   if (first != cmdline.argv().end() && last != cmdline.argv().end())
     flags.insert(first + 1, last);
 #endif
   return flags;
 }
 
 const Experiment::Choice kEnableCompositingForFixedPositionChoices[] = {
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT,
+    "", "", UMA_HISTOGRAM_ID_UNKNOWN_FLAG },
   { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED,
-    switches::kEnableCompositingForFixedPosition, ""},
+    switches::kEnableCompositingForFixedPosition, "",
+    UMA_HISTOGRAM_ID_kEnableCompositingForFixedPosition },
   { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
-    switches::kDisableCompositingForFixedPosition, ""},
+    switches::kDisableCompositingForFixedPosition, "",
+    UMA_HISTOGRAM_ID_kDisableCompositingForFixedPosition },
   { IDS_FLAGS_COMPOSITING_FOR_FIXED_POSITION_HIGH_DPI,
-    switches::kEnableHighDpiCompositingForFixedPosition, ""}
+    switches::kEnableHighDpiCompositingForFixedPosition, "",
+    UMA_HISTOGRAM_ID_kEnableHighDpiCompositingForFixedPosition }
 };
 
 const Experiment::Choice kEnableCompositingForTransitionChoices[] = {
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT,
+    "", "", UMA_HISTOGRAM_ID_UNKNOWN_FLAG },
   { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED,
-    switches::kEnableCompositingForTransition, ""},
+    switches::kEnableCompositingForTransition, "",
+    UMA_HISTOGRAM_ID_kEnableCompositingForTransition },
   { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
-    switches::kDisableCompositingForTransition, ""},
+    switches::kDisableCompositingForTransition, "",
+    UMA_HISTOGRAM_ID_kDisableCompositingForTransition },
 };
 
 const Experiment::Choice kEnableAcceleratedFixedRootBackgroundChoices[] = {
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT,
+    "", "", UMA_HISTOGRAM_ID_UNKNOWN_FLAG },
   { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED,
-    switches::kEnableAcceleratedFixedRootBackground, ""},
+    switches::kEnableAcceleratedFixedRootBackground, "",
+    UMA_HISTOGRAM_ID_kEnableAcceleratedFixedRootBackground },
   { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
-    switches::kDisableAcceleratedFixedRootBackground, ""},
+    switches::kDisableAcceleratedFixedRootBackground, "",
+    UMA_HISTOGRAM_ID_kDisableAcceleratedFixedRootBackground },
 };
 
 const Experiment::Choice kTouchEventsChoices[] = {
-  { IDS_GENERIC_EXPERIMENT_CHOICE_AUTOMATIC, "", "" },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_AUTOMATIC,
+    "",
+    "",
+    UMA_HISTOGRAM_ID_UNKNOWN_FLAG },
   { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED,
     switches::kTouchEvents,
-    switches::kTouchEventsEnabled },
+    switches::kTouchEventsEnabled,
+    UMA_HISTOGRAM_ID_kTouchEvents },
   { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
     switches::kTouchEvents,
-    switches::kTouchEventsDisabled }
+    switches::kTouchEventsDisabled,
+    UMA_HISTOGRAM_ID_kTouchEvents }
 };
 
 #if defined(USE_AURA)
 const Experiment::Choice kOverscrollHistoryNavigationChoices[] = {
-  { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED, "", "" },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED,
+    "",
+    "",
+    UMA_HISTOGRAM_ID_UNKNOWN_FLAG },
   { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
     switches::kOverscrollHistoryNavigation,
-    "0" },
+    "0",
+    UMA_HISTOGRAM_ID_kOverscrollHistoryNavigation },
   { IDS_OVERSCROLL_HISTORY_NAVIGATION_SIMPLE_UI,
     switches::kOverscrollHistoryNavigation,
-    "2" }
+    "2",
+    UMA_HISTOGRAM_ID_kOverscrollHistoryNavigation }
 };
 #endif
 
 #if !defined(DISABLE_NACL)
 const Experiment::Choice kNaClDebugMaskChoices[] = {
   // Secure shell can be used on ChromeOS for forwarding the TCP port opened by
   // debug stub to a remote machine. Since secure shell uses NaCl, we usually
   // want to avoid debugging that. The PNaCl translator is also a NaCl module,
   // so by default we want to avoid debugging that.
   // NOTE: As the default value must be the empty string, the mask excluding
   // the PNaCl translator and secure shell is substituted elsewhere.
-  { IDS_NACL_DEBUG_MASK_CHOICE_EXCLUDE_UTILS_PNACL, "", "" },
-  { IDS_NACL_DEBUG_MASK_CHOICE_DEBUG_ALL, switches::kNaClDebugMask, "*://*" },
-  { IDS_NACL_DEBUG_MASK_CHOICE_INCLUDE_DEBUG,
-      switches::kNaClDebugMask, "*://*/*debug.nmf" }
+  { IDS_NACL_DEBUG_MASK_CHOICE_EXCLUDE_UTILS_PNACL, "", "",
+    UMA_HISTOGRAM_ID_UNKNOWN_FLAG },
+  { IDS_NACL_DEBUG_MASK_CHOICE_DEBUG_ALL, switches::kNaClDebugMask, "*://*",
+    UMA_HISTOGRAM_ID_kNaClDebugMask },
+  { IDS_NACL_DEBUG_MASK_CHOICE_INCLUDE_DEBUG, switches::kNaClDebugMask,
+    "*://*/*debug.nmf", UMA_HISTOGRAM_ID_kNaClDebugMask }
 };
 #endif
 
 const Experiment::Choice kImplSidePaintingChoices[] = {
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
-  { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED,
-    switches::kEnableImplSidePainting, ""},
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
-    switches::kDisableImplSidePainting, ""}
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT,
+    "", "", UMA_HISTOGRAM_ID_UNKNOWN_FLAG },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED,
+    switches::kEnableImplSidePainting, "",
+    UMA_HISTOGRAM_ID_kEnableImplSidePainting },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
+    switches::kDisableImplSidePainting, "",
+    UMA_HISTOGRAM_ID_kDisableImplSidePainting }
 };
 
 const Experiment::Choice kLCDTextChoices[] = {
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
-  { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED, switches::kEnableLCDText, ""},
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED, switches::kDisableLCDText, ""}
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "",
+    UMA_HISTOGRAM_ID_UNKNOWN_FLAG },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED, switches::kEnableLCDText, "",
+    UMA_HISTOGRAM_ID_kEnableLCDText },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED, switches::kDisableLCDText, "",
+    UMA_HISTOGRAM_ID_kDisableLCDText }
 };
 
 const Experiment::Choice kDistanceFieldTextChoices[] = {
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
-  { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED,
-    switches::kEnableDistanceFieldText, "" },
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
-    switches::kDisableDistanceFieldText, "" }
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT,
+    "", "", UMA_HISTOGRAM_ID_UNKNOWN_FLAG },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED,
+    switches::kEnableDistanceFieldText, "",
+    UMA_HISTOGRAM_ID_kEnableDistanceFieldText },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
+    switches::kDisableDistanceFieldText, "",
+    UMA_HISTOGRAM_ID_kDisableDistanceFieldText }
 };
 
 #ifndef USE_AURA
 const Experiment::Choice kDelegatedRendererChoices[] = {
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
-  { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED,
-    switches::kEnableDelegatedRenderer, ""},
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
-    switches::kDisableDelegatedRenderer, ""}
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT,
+    "", "", UMA_HISTOGRAM_ID_UNKNOWN_FLAG },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED,
+    switches::kEnableDelegatedRenderer, "",
+    UMA_HISTOGRAM_ID_kEnableDelegatedRenderer },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
+    switches::kDisableDelegatedRenderer, "",
+    UMA_HISTOGRAM_ID_kDisableDelegatedRenderer }
 };
 #endif
 
 const Experiment::Choice kMaxTilesForInterestAreaChoices[] = {
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT,
+    "", "", UMA_HISTOGRAM_ID_UNKNOWN_FLAG },
   { IDS_FLAGS_MAX_TILES_FOR_INTEREST_AREA_SHORT,
-    cc::switches::kMaxTilesForInterestArea, "64"},
+    cc::switches::kMaxTilesForInterestArea, "64",
+    UMA_HISTOGRAM_ID_kMaxTilesForInterestArea },
   { IDS_FLAGS_MAX_TILES_FOR_INTEREST_AREA_TALL,
-    cc::switches::kMaxTilesForInterestArea, "128"},
+    cc::switches::kMaxTilesForInterestArea, "128",
+    UMA_HISTOGRAM_ID_kMaxTilesForInterestArea },
   { IDS_FLAGS_MAX_TILES_FOR_INTEREST_AREA_GRANDE,
-    cc::switches::kMaxTilesForInterestArea, "256"},
+    cc::switches::kMaxTilesForInterestArea, "256",
+    UMA_HISTOGRAM_ID_kMaxTilesForInterestArea },
   { IDS_FLAGS_MAX_TILES_FOR_INTEREST_AREA_VENTI,
-    cc::switches::kMaxTilesForInterestArea, "512"}
+    cc::switches::kMaxTilesForInterestArea, "512",
+    UMA_HISTOGRAM_ID_kMaxTilesForInterestArea }
 };
 
 const Experiment::Choice kDefaultTileWidthChoices[] = {
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT,
+    "", "", UMA_HISTOGRAM_ID_UNKNOWN_FLAG },
   { IDS_FLAGS_DEFAULT_TILE_WIDTH_SHORT,
-    switches::kDefaultTileWidth, "128"},
+    switches::kDefaultTileWidth, "128", UMA_HISTOGRAM_ID_kDefaultTileWidth },
   { IDS_FLAGS_DEFAULT_TILE_WIDTH_TALL,
-    switches::kDefaultTileWidth, "256"},
+    switches::kDefaultTileWidth, "256", UMA_HISTOGRAM_ID_kDefaultTileWidth },
   { IDS_FLAGS_DEFAULT_TILE_WIDTH_GRANDE,
-    switches::kDefaultTileWidth, "512"},
+    switches::kDefaultTileWidth, "512", UMA_HISTOGRAM_ID_kDefaultTileWidth },
   { IDS_FLAGS_DEFAULT_TILE_WIDTH_VENTI,
-    switches::kDefaultTileWidth, "1024"}
+    switches::kDefaultTileWidth, "1024", UMA_HISTOGRAM_ID_kDefaultTileWidth }
 };
 
 const Experiment::Choice kDefaultTileHeightChoices[] = {
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT,
+    "", "", UMA_HISTOGRAM_ID_UNKNOWN_FLAG },
   { IDS_FLAGS_DEFAULT_TILE_HEIGHT_SHORT,
-    switches::kDefaultTileHeight, "128"},
+    switches::kDefaultTileHeight, "128", UMA_HISTOGRAM_ID_kDefaultTileHeight },
   { IDS_FLAGS_DEFAULT_TILE_HEIGHT_TALL,
-    switches::kDefaultTileHeight, "256"},
+    switches::kDefaultTileHeight, "256", UMA_HISTOGRAM_ID_kDefaultTileHeight },
   { IDS_FLAGS_DEFAULT_TILE_HEIGHT_GRANDE,
-    switches::kDefaultTileHeight, "512"},
+    switches::kDefaultTileHeight, "512", UMA_HISTOGRAM_ID_kDefaultTileHeight },
   { IDS_FLAGS_DEFAULT_TILE_HEIGHT_VENTI,
-    switches::kDefaultTileHeight, "1024"}
+    switches::kDefaultTileHeight, "1024", UMA_HISTOGRAM_ID_kDefaultTileHeight }
 };
 
 const Experiment::Choice kSimpleCacheBackendChoices[] = {
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
-    switches::kUseSimpleCacheBackend, "off" },
-  { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED,
-    switches::kUseSimpleCacheBackend, "on"}
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT,
+    "", "", UMA_HISTOGRAM_ID_UNKNOWN_FLAG },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
+    switches::kUseSimpleCacheBackend, "off",
+    UMA_HISTOGRAM_ID_kUseSimpleCacheBackend },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED,
+    switches::kUseSimpleCacheBackend, "on",
+    UMA_HISTOGRAM_ID_kUseSimpleCacheBackend }
 };
 
 #if defined(USE_AURA)
 const Experiment::Choice kTabCaptureUpscaleQualityChoices[] = {
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT,
+    "", "", UMA_HISTOGRAM_ID_UNKNOWN_FLAG },
   { IDS_FLAGS_TAB_CAPTURE_SCALE_QUALITY_FAST,
-    switches::kTabCaptureUpscaleQuality, "fast" },
+    switches::kTabCaptureUpscaleQuality, "fast",
+    UMA_HISTOGRAM_ID_kTabCaptureUpscaleQuality },
   { IDS_FLAGS_TAB_CAPTURE_SCALE_QUALITY_GOOD,
-    switches::kTabCaptureUpscaleQuality, "good" },
+    switches::kTabCaptureUpscaleQuality, "good",
+    UMA_HISTOGRAM_ID_kTabCaptureUpscaleQuality },
   { IDS_FLAGS_TAB_CAPTURE_SCALE_QUALITY_BEST,
-    switches::kTabCaptureUpscaleQuality, "best" },
+    switches::kTabCaptureUpscaleQuality, "best",
+    UMA_HISTOGRAM_ID_kTabCaptureUpscaleQuality },
 };
 
 const Experiment::Choice kTabCaptureDownscaleQualityChoices[] = {
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT,
+    "", "", UMA_HISTOGRAM_ID_UNKNOWN_FLAG },
   { IDS_FLAGS_TAB_CAPTURE_SCALE_QUALITY_FAST,
-    switches::kTabCaptureDownscaleQuality, "fast" },
+    switches::kTabCaptureDownscaleQuality, "fast",
+    UMA_HISTOGRAM_ID_kTabCaptureDownscaleQuality },
   { IDS_FLAGS_TAB_CAPTURE_SCALE_QUALITY_GOOD,
-    switches::kTabCaptureDownscaleQuality, "good" },
+    switches::kTabCaptureDownscaleQuality, "good",
+    UMA_HISTOGRAM_ID_kTabCaptureDownscaleQuality },
   { IDS_FLAGS_TAB_CAPTURE_SCALE_QUALITY_BEST,
-    switches::kTabCaptureDownscaleQuality, "best" },
+    switches::kTabCaptureDownscaleQuality, "best",
+    UMA_HISTOGRAM_ID_kTabCaptureDownscaleQuality },
 };
 #endif
 
 #if defined(USE_AURA) || defined(OS_LINUX)
 const Experiment::Choice kOverlayScrollbarChoices[] = {
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
-  { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED,
-    switches::kEnableOverlayScrollbar, ""},
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
-    switches::kDisableOverlayScrollbar, ""}
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT,
+    "", "", UMA_HISTOGRAM_ID_UNKNOWN_FLAG },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED,
+    switches::kEnableOverlayScrollbar, "",
+    UMA_HISTOGRAM_ID_kEnableOverlayScrollbar },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
+    switches::kDisableOverlayScrollbar, "",
+    UMA_HISTOGRAM_ID_kDisableOverlayScrollbar }
 };
 #endif
 
 const Experiment::Choice kZeroCopyChoices[] = {
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
-  { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED,
-    switches::kEnableZeroCopy, ""},
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
-    switches::kDisableZeroCopy, ""}
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT,
+    "", "", UMA_HISTOGRAM_ID_UNKNOWN_FLAG },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED,
+    switches::kEnableZeroCopy, "", UMA_HISTOGRAM_ID_kEnableZeroCopy },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
+    switches::kDisableZeroCopy, "", UMA_HISTOGRAM_ID_kDisableZeroCopy }
 };
 
 #if defined(OS_ANDROID)
 const Experiment::Choice kZeroSuggestExperimentsChoices[] = {
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT,
+    "", "", UMA_HISTOGRAM_ID_UNKNOWN_FLAG },
   { IDS_FLAGS_ZERO_SUGGEST_MOST_VISITED,
-    switches::kEnableZeroSuggestMostVisited, ""},
+    switches::kEnableZeroSuggestMostVisited, "",
+    UMA_HISTOGRAM_ID_kEnableZeroSuggestMostVisited },
   { IDS_FLAGS_ZERO_SUGGEST_ETHER_SERP,
-    switches::kEnableZeroSuggestEtherSerp, ""},
+    switches::kEnableZeroSuggestEtherSerp, "",
+    UMA_HISTOGRAM_ID_kEnableZeroSuggestEtherSerp },
   { IDS_FLAGS_ZERO_SUGGEST_ETHER_NO_SERP,
-    switches::kEnableZeroSuggestEtherNoSerp, ""},
+    switches::kEnableZeroSuggestEtherNoSerp, "",
+    UMA_HISTOGRAM_ID_kEnableZeroSuggestEtherNoSerp },
   { IDS_FLAGS_ZERO_SUGGEST_PERSONALIZED,
-    switches::kEnableZeroSuggestPersonalized, ""},
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
-    switches::kDisableZeroSuggest, ""}
+    switches::kEnableZeroSuggestPersonalized, "",
+    UMA_HISTOGRAM_ID_kEnableZeroSuggestPersonalized },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
+    switches::kDisableZeroSuggest, "", UMA_HISTOGRAM_ID_kDisableZeroSuggest }
 };
 #endif
 
 const Experiment::Choice kNumRasterThreadsChoices[] = {
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
-  { IDS_FLAGS_NUM_RASTER_THREADS_ONE, switches::kNumRasterThreads, "1" },
-  { IDS_FLAGS_NUM_RASTER_THREADS_TWO, switches::kNumRasterThreads, "2" },
-  { IDS_FLAGS_NUM_RASTER_THREADS_THREE, switches::kNumRasterThreads, "3" },
-  { IDS_FLAGS_NUM_RASTER_THREADS_FOUR, switches::kNumRasterThreads, "4" }
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT,
+    "", "", UMA_HISTOGRAM_ID_UNKNOWN_FLAG },
+  { IDS_FLAGS_NUM_RASTER_THREADS_ONE,
+    switches::kNumRasterThreads, "1", UMA_HISTOGRAM_ID_kNumRasterThreads },
+  { IDS_FLAGS_NUM_RASTER_THREADS_TWO,
+    switches::kNumRasterThreads, "2", UMA_HISTOGRAM_ID_kNumRasterThreads },
+  { IDS_FLAGS_NUM_RASTER_THREADS_THREE,
+    switches::kNumRasterThreads, "3", UMA_HISTOGRAM_ID_kNumRasterThreads },
+  { IDS_FLAGS_NUM_RASTER_THREADS_FOUR,
+    switches::kNumRasterThreads, "4", UMA_HISTOGRAM_ID_kNumRasterThreads }
 };
 
 const Experiment::Choice kEnableGpuRasterizationChoices[] = {
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
-  { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED,
-    switches::kEnableGpuRasterization, "" },
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
-    switches::kDisableGpuRasterization, "" },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT,
+    "", "", UMA_HISTOGRAM_ID_UNKNOWN_FLAG },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED,
+    switches::kEnableGpuRasterization, "",
+    UMA_HISTOGRAM_ID_kEnableGpuRasterization },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
+    switches::kDisableGpuRasterization, "",
+    UMA_HISTOGRAM_ID_kDisableGpuRasterization },
   { IDS_FLAGS_FORCE_GPU_RASTERIZATION,
-    switches::kForceGpuRasterization, "" },
+    switches::kForceGpuRasterization, "",
+    UMA_HISTOGRAM_ID_kForceGpuRasterization },
 };
 
 // We're using independent flags here (as opposed to a common flag with
 // different values) to be able to enable/disable the entire experience
 // associated with this feature server-side from the FieldTrial (the complete
 // experience includes other flag changes as well). It is not currently possible
 // to do that with "flag=value" flags.
 const Experiment::Choice kSearchButtonInOmniboxChoices[] = {
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT,
+    "", "", UMA_HISTOGRAM_ID_UNKNOWN_FLAG },
   { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
-    switches::kDisableSearchButtonInOmnibox, ""},
+    switches::kDisableSearchButtonInOmnibox, "",
+    UMA_HISTOGRAM_ID_kDisableSearchButtonInOmnibox },
   { IDS_FLAGS_SEARCH_BUTTON_IN_OMNIBOX_ENABLE_FOR_STR,
-    switches::kEnableSearchButtonInOmniboxForStr, ""},
+    switches::kEnableSearchButtonInOmniboxForStr, "",
+    UMA_HISTOGRAM_ID_kEnableSearchButtonInOmniboxForStr },
   { IDS_FLAGS_SEARCH_BUTTON_IN_OMNIBOX_ENABLE_FOR_STR_OR_IIP,
-    switches::kEnableSearchButtonInOmniboxForStrOrIip, ""},
+    switches::kEnableSearchButtonInOmniboxForStrOrIip, "",
+    UMA_HISTOGRAM_ID_kEnableSearchButtonInOmniboxForStrOrIip },
   { IDS_FLAGS_SEARCH_BUTTON_IN_OMNIBOX_ENABLED,
-    switches::kEnableSearchButtonInOmniboxAlways, ""}
+    switches::kEnableSearchButtonInOmniboxAlways, "",
+    UMA_HISTOGRAM_ID_kEnableSearchButtonInOmniboxAlways }
 };
 
 // See comment above for kSearchButtonInOmniboxChoices. The same reasoning
 // applies here.
 const Experiment::Choice kOriginChipChoices[] = {
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED, switches::kDisableOriginChip, ""},
-  { IDS_FLAGS_ORIGIN_CHIP_ALWAYS, switches::kEnableOriginChipAlways, ""},
-  { IDS_FLAGS_ORIGIN_CHIP_ON_SRP, switches::kEnableOriginChipOnSrp, ""}
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT,
+    "", "", UMA_HISTOGRAM_ID_UNKNOWN_FLAG },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
+    switches::kDisableOriginChip, "", UMA_HISTOGRAM_ID_kDisableOriginChip },
+  { IDS_FLAGS_ORIGIN_CHIP_ALWAYS,
+    switches::kEnableOriginChipAlways, "",
+    UMA_HISTOGRAM_ID_kEnableOriginChipAlways },
+  { IDS_FLAGS_ORIGIN_CHIP_ON_SRP,
+    switches::kEnableOriginChipOnSrp, "",
+    UMA_HISTOGRAM_ID_kEnableOriginChipOnSrp }
 };
 
 const Experiment::Choice kTouchScrollingModeChoices[] = {
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT,
+    "", "", UMA_HISTOGRAM_ID_UNKNOWN_FLAG },
   { IDS_FLAGS_TOUCH_SCROLLING_MODE_TOUCHCANCEL,
     switches::kTouchScrollingMode,
-    switches::kTouchScrollingModeTouchcancel },
+    switches::kTouchScrollingModeTouchcancel,
+    UMA_HISTOGRAM_ID_kTouchScrollingMode },
   { IDS_FLAGS_TOUCH_SCROLLING_MODE_ASYNC_TOUCHMOVE,
     switches::kTouchScrollingMode,
-    switches::kTouchScrollingModeAsyncTouchmove },
+    switches::kTouchScrollingModeAsyncTouchmove,
+    UMA_HISTOGRAM_ID_kTouchScrollingMode },
   { IDS_FLAGS_TOUCH_SCROLLING_MODE_SYNC_TOUCHMOVE,
     switches::kTouchScrollingMode,
-    switches::kTouchScrollingModeSyncTouchmove },
+    switches::kTouchScrollingModeSyncTouchmove,
+    UMA_HISTOGRAM_ID_kTouchScrollingMode },
 };
 
 #if defined(ENABLE_APP_LIST)
 const Experiment::Choice kEnableSyncAppListChoices[] = {
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT,
+    "", "", UMA_HISTOGRAM_ID_UNKNOWN_FLAG },
   { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED,
-    app_list::switches::kEnableSyncAppList, "" },
+    app_list::switches::kEnableSyncAppList, "",
+    UMA_HISTOGRAM_ID_kEnableSyncAppList },
   { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
-    app_list::switches::kDisableSyncAppList, "" },
+    app_list::switches::kDisableSyncAppList, "",
+    UMA_HISTOGRAM_ID_kDisableSyncAppList },
 };
 #endif
 
 const Experiment::Choice kExtensionContentVerificationChoices[] = {
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT,
+    "", "", UMA_HISTOGRAM_ID_UNKNOWN_FLAG },
   { IDS_FLAGS_EXTENSION_CONTENT_VERIFICATION_BOOTSTRAP,
     extensions::switches::kExtensionContentVerification,
-    extensions::switches::kExtensionContentVerificationBootstrap },
+    extensions::switches::kExtensionContentVerificationBootstrap,
+    UMA_HISTOGRAM_ID_kExtensionContentVerification },
   { IDS_FLAGS_EXTENSION_CONTENT_VERIFICATION_ENFORCE,
     extensions::switches::kExtensionContentVerification,
-    extensions::switches::kExtensionContentVerificationEnforce },
+    extensions::switches::kExtensionContentVerificationEnforce,
+    UMA_HISTOGRAM_ID_kExtensionContentVerification },
   { IDS_FLAGS_EXTENSION_CONTENT_VERIFICATION_ENFORCE_STRICT,
     extensions::switches::kExtensionContentVerification,
-    extensions::switches::kExtensionContentVerificationEnforceStrict },
+    extensions::switches::kExtensionContentVerificationEnforceStrict,
+    UMA_HISTOGRAM_ID_kExtensionContentVerification },
 };
 
 // Using independent flags (instead of flag=value flags) to be able to
 // associate the version with a FieldTrial. FieldTrials don't currently support
 // flag=value flags.
 const Experiment::Choice kSSLInterstitialVersions[] = {
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT,
+    "", "", UMA_HISTOGRAM_ID_UNKNOWN_FLAG },
   { IDS_FLAGS_SSL_INTERSTITIAL_VERSION_V1,
-    switches::kSSLInterstitialVersionV1, "" },
+    switches::kSSLInterstitialVersionV1, "",
+    UMA_HISTOGRAM_ID_kSSLInterstitialVersionV1 },
   { IDS_FLAGS_SSL_INTERSTITIAL_VERSION_V2_GRAY,
-    switches::kSSLInterstitialVersionV2Gray, "" },
+    switches::kSSLInterstitialVersionV2Gray, "",
+    UMA_HISTOGRAM_ID_kSSLInterstitialVersionV2Gray },
   { IDS_FLAGS_SSL_INTERSTITIAL_VERSION_V2_COLORFUL,
-    switches::kSSLInterstitialVersionV2Colorful, "" },
+    switches::kSSLInterstitialVersionV2Colorful, "",
+    UMA_HISTOGRAM_ID_kSSLInterstitialVersionV2Colorful },
 };
 
 // Using independent flags (instead of flag=value flags) to be able to
 // associate the version with a FieldTrial. FieldTrials don't currently support
 // flag=value flags.
 const Experiment::Choice kMalwareInterstitialVersions[] = {
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT,
+    "", "", UMA_HISTOGRAM_ID_UNKNOWN_FLAG },
   { IDS_FLAGS_MALWARE_INTERSTITIAL_VERSION_V2,
-    switches::kMalwareInterstitialVersionV2, "" },
+    switches::kMalwareInterstitialVersionV2, "",
+    UMA_HISTOGRAM_ID_kMalwareInterstitialVersionV2 },
   { IDS_FLAGS_MALWARE_INTERSTITIAL_VERSION_V3,
-    switches::kMalwareInterstitialVersionV3, "" },
+    switches::kMalwareInterstitialVersionV3, "",
+    UMA_HISTOGRAM_ID_kMalwareInterstitialVersionV3 },
 };
 
 #if defined(OS_CHROMEOS)
 const Experiment::Choice kEnableFileManagerMTPChoices[] = {
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT,
+    "", "", UMA_HISTOGRAM_ID_UNKNOWN_FLAG },
   { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED,
-    chromeos::switches::kEnableFileManagerMTP, "true" },
+    chromeos::switches::kEnableFileManagerMTP, "true",
+    UMA_HISTOGRAM_ID_kEnableFileManagerMTP },
   { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
-    chromeos::switches::kEnableFileManagerMTP, "false" }
+    chromeos::switches::kEnableFileManagerMTP, "false",
+    UMA_HISTOGRAM_ID_kEnableFileManagerMTP }
 };
 
 const Experiment::Choice kEnableFileManagerNewGalleryChoices[] = {
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", ""},
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT,
+    "", "", UMA_HISTOGRAM_ID_UNKNOWN_FLAG },
   { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED,
-    chromeos::switches::kFileManagerEnableNewGallery, "true"},
+    chromeos::switches::kFileManagerEnableNewGallery, "true",
+    UMA_HISTOGRAM_ID_kFileManagerEnableNewGallery },
   { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
-    chromeos::switches::kFileManagerEnableNewGallery, "false"}
+    chromeos::switches::kFileManagerEnableNewGallery, "false",
+    UMA_HISTOGRAM_ID_kFileManagerEnableNewGallery }
 };
 #endif
 
 const Experiment::Choice kEnableSettingsWindowChoices[] = {
-  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT,
+    "", "", UMA_HISTOGRAM_ID_UNKNOWN_FLAG },
   { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED,
-    ::switches::kEnableSettingsWindow, "" },
+    ::switches::kEnableSettingsWindow, "",
+    UMA_HISTOGRAM_ID_kEnableSettingsWindow },
   { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
-    ::switches::kDisableSettingsWindow, "" },
+    ::switches::kDisableSettingsWindow, "",
+    UMA_HISTOGRAM_ID_kDisableSettingsWindow },
 };
 
 // RECORDING USER METRICS FOR FLAGS:
 // -----------------------------------------------------------------------------
 // The first line of the experiment is the internal name. If you'd like to
 // gather statistics about the usage of your flag, you should append a marker
 // comment to the end of the feature name, like so:
 //   "my-special-feature",  // FLAGS:RECORD_UMA
 //
 // After doing that, run
@@ skipping 24 matching lines @@
 //   array of choices.
 // See the documentation of Experiment for details on the fields.
 //
 // When adding a new choice, add it to the end of the list.
 const Experiment kExperiments[] = {
   {
     "ignore-gpu-blacklist",
     IDS_FLAGS_IGNORE_GPU_BLACKLIST_NAME,
     IDS_FLAGS_IGNORE_GPU_BLACKLIST_DESCRIPTION,
     kOsAll,
-    SINGLE_VALUE_TYPE(switches::kIgnoreGpuBlacklist)
+    SINGLE_VALUE_TYPE(switches::kIgnoreGpuBlacklist,
+                      UMA_HISTOGRAM_ID_kIgnoreGpuBlacklist)
   },
   {
     "threaded-compositing-mode",
     IDS_FLAGS_THREADED_COMPOSITING_MODE_NAME,
     IDS_FLAGS_THREADED_COMPOSITING_MODE_DESCRIPTION,
 #if !defined(USE_AURA)
     kOsLinux,
 #else
     0,
 #endif
     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableThreadedCompositing,
-                              switches::kDisableThreadedCompositing)
+                              UMA_HISTOGRAM_ID_kEnableThreadedCompositing,
+                              switches::kDisableThreadedCompositing,
+                              UMA_HISTOGRAM_ID_kDisableThreadedCompositing)
   },
   {
     "force-accelerated-composited-scrolling",
-     IDS_FLAGS_FORCE_ACCELERATED_OVERFLOW_SCROLL_MODE_NAME,
-     IDS_FLAGS_FORCE_ACCELERATED_OVERFLOW_SCROLL_MODE_DESCRIPTION,
-     kOsAll,
-     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableAcceleratedOverflowScroll,
-                               switches::kDisableAcceleratedOverflowScroll)
+    IDS_FLAGS_FORCE_ACCELERATED_OVERFLOW_SCROLL_MODE_NAME,
+    IDS_FLAGS_FORCE_ACCELERATED_OVERFLOW_SCROLL_MODE_DESCRIPTION, kOsAll,
+    ENABLE_DISABLE_VALUE_TYPE(
+        switches::kEnableAcceleratedOverflowScroll,
+        UMA_HISTOGRAM_ID_kEnableAcceleratedOverflowScroll,
+        switches::kDisableAcceleratedOverflowScroll,
+        UMA_HISTOGRAM_ID_kDisableAcceleratedOverflowScroll)
   },
   {
     "disable_layer_squashing",
     IDS_FLAGS_DISABLE_LAYER_SQUASHING_NAME,
     IDS_FLAGS_DISABLE_LAYER_SQUASHING_DESCRIPTION,
     kOsAll,
-    SINGLE_VALUE_TYPE(switches::kDisableLayerSquashing)
+    SINGLE_VALUE_TYPE(switches::kDisableLayerSquashing,
+                      UMA_HISTOGRAM_ID_kDisableLayerSquashing)
   },
 #if defined(OS_WIN)
   {
     "disable-direct-write",
     IDS_FLAGS_DISABLE_DIRECT_WRITE_NAME,
     IDS_FLAGS_DISABLE_DIRECT_WRITE_DESCRIPTION,
     kOsWin,
-    SINGLE_VALUE_TYPE(switches::kDisableDirectWrite)
+    SINGLE_VALUE_TYPE(switches::kDisableDirectWrite,
+                      UMA_HISTOGRAM_ID_kDisableDirectWrite)
   },
 #endif
   {
     "enable-experimental-canvas-features",
     IDS_FLAGS_ENABLE_EXPERIMENTAL_CANVAS_FEATURES_NAME,
     IDS_FLAGS_ENABLE_EXPERIMENTAL_CANVAS_FEATURES_DESCRIPTION,
     kOsAll,
-    SINGLE_VALUE_TYPE(switches::kEnableExperimentalCanvasFeatures)
+    SINGLE_VALUE_TYPE(switches::kEnableExperimentalCanvasFeatures,
+                      UMA_HISTOGRAM_ID_kEnableExperimentalCanvasFeatures)
   },
   {
     "disable-accelerated-2d-canvas",
     IDS_FLAGS_DISABLE_ACCELERATED_2D_CANVAS_NAME,
     IDS_FLAGS_DISABLE_ACCELERATED_2D_CANVAS_DESCRIPTION,
     kOsAll,
-    SINGLE_VALUE_TYPE(switches::kDisableAccelerated2dCanvas)
+    SINGLE_VALUE_TYPE(switches::kDisableAccelerated2dCanvas,
+                      UMA_HISTOGRAM_ID_kDisableAccelerated2dCanvas)
   },
   {
     "composited-layer-borders",
     IDS_FLAGS_COMPOSITED_LAYER_BORDERS,
     IDS_FLAGS_COMPOSITED_LAYER_BORDERS_DESCRIPTION,
     kOsAll,
-    SINGLE_VALUE_TYPE(cc::switches::kShowCompositedLayerBorders)
+    SINGLE_VALUE_TYPE(cc::switches::kShowCompositedLayerBorders,
+                      UMA_HISTOGRAM_ID_kShowCompositedLayerBorders)
   },
   {
     "show-fps-counter",
     IDS_FLAGS_SHOW_FPS_COUNTER,
     IDS_FLAGS_SHOW_FPS_COUNTER_DESCRIPTION,
     kOsAll,
-    SINGLE_VALUE_TYPE(cc::switches::kShowFPSCounter)
+    SINGLE_VALUE_TYPE(cc::switches::kShowFPSCounter,
+                      UMA_HISTOGRAM_ID_kShowFPSCounter)
   },
   {
     "disable-webgl",
     IDS_FLAGS_DISABLE_WEBGL_NAME,
     IDS_FLAGS_DISABLE_WEBGL_DESCRIPTION,
     kOsAll,
-    SINGLE_VALUE_TYPE(switches::kDisableExperimentalWebGL)
+    SINGLE_VALUE_TYPE(switches::kDisableExperimentalWebGL,
+                      UMA_HISTOGRAM_ID_kDisableExperimentalWebGL)
   },
   {
     "disable-webrtc",
     IDS_FLAGS_DISABLE_WEBRTC_NAME,
     IDS_FLAGS_DISABLE_WEBRTC_DESCRIPTION,
     kOsAndroid,
 #if defined(OS_ANDROID)
-    SINGLE_VALUE_TYPE(switches::kDisableWebRTC)
+    SINGLE_VALUE_TYPE(switches::kDisableWebRTC,
+                      UMA_HISTOGRAM_ID_kDisableWebRTC)
 #else
-    SINGLE_VALUE_TYPE("")
+    SINGLE_VALUE_TYPE("", 0)
 #endif
   },
 #if defined(ENABLE_WEBRTC)
   {
     "disable-device-enumeration",
     IDS_FLAGS_DISABLE_DEVICE_ENUMERATION_NAME,
     IDS_FLAGS_DISABLE_DEVICE_ENUMERATION_DESCRIPTION,
     kOsAll,
-    SINGLE_VALUE_TYPE(switches::kDisableDeviceEnumeration)
+    SINGLE_VALUE_TYPE(switches::kDisableDeviceEnumeration,
+                      UMA_HISTOGRAM_ID_kDisableDeviceEnumeration)
   },
   {
     "disable-webrtc-hw-decoding",
     IDS_FLAGS_DISABLE_WEBRTC_HW_DECODING_NAME,
     IDS_FLAGS_DISABLE_WEBRTC_HW_DECODING_DESCRIPTION,
     kOsAndroid | kOsCrOS,
-    SINGLE_VALUE_TYPE(switches::kDisableWebRtcHWDecoding)
+    SINGLE_VALUE_TYPE(switches::kDisableWebRtcHWDecoding,
+                      UMA_HISTOGRAM_ID_kDisableWebRtcHWDecoding)
   },
   {
     "disable-webrtc-hw-encoding",
     IDS_FLAGS_DISABLE_WEBRTC_HW_ENCODING_NAME,
     IDS_FLAGS_DISABLE_WEBRTC_HW_ENCODING_DESCRIPTION,
     kOsAndroid | kOsCrOS,
-    SINGLE_VALUE_TYPE(switches::kDisableWebRtcHWEncoding)
+    SINGLE_VALUE_TYPE(switches::kDisableWebRtcHWEncoding,
+                      UMA_HISTOGRAM_ID_kDisableWebRtcHWEncoding)
   },
 #endif
 #if defined(OS_ANDROID)
   {
     "disable-webaudio",
     IDS_FLAGS_DISABLE_WEBAUDIO_NAME,
     IDS_FLAGS_DISABLE_WEBAUDIO_DESCRIPTION,
     kOsAndroid,
-    SINGLE_VALUE_TYPE(switches::kDisableWebAudio)
+    SINGLE_VALUE_TYPE(switches::kDisableWebAudio,
+                      UMA_HISTOGRAM_ID_kDisableWebAudio)
   },
 #endif
   {
     "enable-compositing-for-fixed-position",
     IDS_FLAGS_COMPOSITING_FOR_FIXED_POSITION_NAME,
     IDS_FLAGS_COMPOSITING_FOR_FIXED_POSITION_DESCRIPTION,
     kOsAll,
     MULTI_VALUE_TYPE(kEnableCompositingForFixedPositionChoices)
   },
   {
@@ skipping 10 matching lines @@
     kOsAll,
     MULTI_VALUE_TYPE(kEnableAcceleratedFixedRootBackgroundChoices)
   },
   // Native client is compiled out when DISABLE_NACL is defined.
 #if !defined(DISABLE_NACL)
   {
     "enable-nacl",  // FLAGS:RECORD_UMA
     IDS_FLAGS_ENABLE_NACL_NAME,
     IDS_FLAGS_ENABLE_NACL_DESCRIPTION,
     kOsAll,
-    SINGLE_VALUE_TYPE(switches::kEnableNaCl)
+    SINGLE_VALUE_TYPE(switches::kEnableNaCl, UMA_HISTOGRAM_ID_kEnableNaCl)
   },
   {
     "enable-nacl-debug",  // FLAGS:RECORD_UMA
     IDS_FLAGS_ENABLE_NACL_DEBUG_NAME,
     IDS_FLAGS_ENABLE_NACL_DEBUG_DESCRIPTION,
     kOsDesktop,
-    SINGLE_VALUE_TYPE(switches::kEnableNaClDebug)
+    SINGLE_VALUE_TYPE(switches::kEnableNaClDebug,
+                      UMA_HISTOGRAM_ID_kEnableNaClDebug)
   },
   {
     "disable-pnacl",  // FLAGS:RECORD_UMA
     IDS_FLAGS_DISABLE_PNACL_NAME,
     IDS_FLAGS_DISABLE_PNACL_DESCRIPTION,
     kOsDesktop,
-    SINGLE_VALUE_TYPE(switches::kDisablePnacl)
+    SINGLE_VALUE_TYPE(switches::kDisablePnacl,
+                      UMA_HISTOGRAM_ID_kDisablePnacl)
   },
   {
     "nacl-debug-mask",  // FLAGS:RECORD_UMA
     IDS_FLAGS_NACL_DEBUG_MASK_NAME,
     IDS_FLAGS_NACL_DEBUG_MASK_DESCRIPTION,
     kOsDesktop,
     MULTI_VALUE_TYPE(kNaClDebugMaskChoices)
   },
 #endif
   {
     "extension-apis",  // FLAGS:RECORD_UMA
     IDS_FLAGS_EXPERIMENTAL_EXTENSION_APIS_NAME,
     IDS_FLAGS_EXPERIMENTAL_EXTENSION_APIS_DESCRIPTION,
     kOsDesktop,
-    SINGLE_VALUE_TYPE(extensions::switches::kEnableExperimentalExtensionApis)
+    SINGLE_VALUE_TYPE(extensions::switches::kEnableExperimentalExtensionApis,
+                      UMA_HISTOGRAM_ID_kEnableExperimentalExtensionApis)
   },
   {
     "extensions-on-chrome-urls",
     IDS_FLAGS_EXTENSIONS_ON_CHROME_URLS_NAME,
     IDS_FLAGS_EXTENSIONS_ON_CHROME_URLS_DESCRIPTION,
     kOsAll,
-    SINGLE_VALUE_TYPE(extensions::switches::kExtensionsOnChromeURLs)
+    SINGLE_VALUE_TYPE(extensions::switches::kExtensionsOnChromeURLs,
+                      UMA_HISTOGRAM_ID_kExtensionsOnChromeURLs)
   },
   {
     "enable-fast-unload",
     IDS_FLAGS_ENABLE_FAST_UNLOAD_NAME,
     IDS_FLAGS_ENABLE_FAST_UNLOAD_DESCRIPTION,
     kOsAll,
-    SINGLE_VALUE_TYPE(switches::kEnableFastUnload)
+    SINGLE_VALUE_TYPE(switches::kEnableFastUnload,
+                      UMA_HISTOGRAM_ID_kEnableFastUnload)
   },
   {
     "enable-app-window-controls",
     IDS_FLAGS_ENABLE_APP_WINDOW_CONTROLS_NAME,
     IDS_FLAGS_ENABLE_APP_WINDOW_CONTROLS_DESCRIPTION,
     kOsDesktop,
-    SINGLE_VALUE_TYPE(switches::kEnableAppWindowControls)
+    SINGLE_VALUE_TYPE(switches::kEnableAppWindowControls,
+                      UMA_HISTOGRAM_ID_kEnableAppWindowControls)
   },
   {
     "disable-hyperlink-auditing",
     IDS_FLAGS_DISABLE_HYPERLINK_AUDITING_NAME,
     IDS_FLAGS_DISABLE_HYPERLINK_AUDITING_DESCRIPTION,
     kOsAll,
-    SINGLE_VALUE_TYPE(switches::kNoPings)
+    SINGLE_VALUE_TYPE(switches::kNoPings, UMA_HISTOGRAM_ID_kNoPings)
   },
 #if defined(OS_ANDROID)
   {
     "enable-new-ntp",
     IDS_FLAGS_ENABLE_NEW_NTP,
     IDS_FLAGS_ENABLE_NEW_NTP_DESCRIPTION,
     kOsAndroid,
     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableNewNTP,
-                              switches::kDisableNewNTP)
+                              UMA_HISTOGRAM_ID_kEnableNewNTP,
+                              switches::kDisableNewNTP,
+                              UMA_HISTOGRAM_ID_kDisableNewNTP)
   },
   {
     "contextual-search",
     IDS_FLAGS_ENABLE_CONTEXTUAL_SEARCH,
     IDS_FLAGS_ENABLE_CONTEXTUAL_SEARCH_DESCRIPTION,
     kOsAndroid,
     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableContextualSearch,
-                              switches::kDisableContextualSearch)
+                              UMA_HISTOGRAM_ID_kEnableContextualSearch,
+                              switches::kDisableContextualSearch,
+                              UMA_HISTOGRAM_ID_kDisableContextualSearch)
   },
 #endif
   {
     "show-autofill-type-predictions",
     IDS_FLAGS_SHOW_AUTOFILL_TYPE_PREDICTIONS_NAME,
     IDS_FLAGS_SHOW_AUTOFILL_TYPE_PREDICTIONS_DESCRIPTION,
     kOsAll,
-    SINGLE_VALUE_TYPE(autofill::switches::kShowAutofillTypePredictions)
+    SINGLE_VALUE_TYPE(autofill::switches::kShowAutofillTypePredictions,
+                      UMA_HISTOGRAM_ID_kShowAutofillTypePredictions)
   },
   {
     "enable-gesture-tap-highlight",
     IDS_FLAGS_ENABLE_GESTURE_TAP_HIGHLIGHTING_NAME,
     IDS_FLAGS_ENABLE_GESTURE_TAP_HIGHLIGHTING_DESCRIPTION,
     kOsLinux | kOsCrOS | kOsWin | kOsAndroid,
     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableGestureTapHighlight,
-                              switches::kDisableGestureTapHighlight)
+                              UMA_HISTOGRAM_ID_kEnableGestureTapHighlight,
+                              switches::kDisableGestureTapHighlight,
+                              UMA_HISTOGRAM_ID_kDisableGestureTapHighlight)
   },
   {
     "enable-smooth-scrolling",  // FLAGS:RECORD_UMA
     IDS_FLAGS_ENABLE_SMOOTH_SCROLLING_NAME,
     IDS_FLAGS_ENABLE_SMOOTH_SCROLLING_DESCRIPTION,
     // Can't expose the switch unless the code is compiled in.
     // On by default for the Mac (different implementation in WebKit).
     kOsLinux,
-    SINGLE_VALUE_TYPE(switches::kEnableSmoothScrolling)
+    SINGLE_VALUE_TYPE(switches::kEnableSmoothScrolling,
+                                UMA_HISTOGRAM_ID_kEnableSmoothScrolling)
   },
 #if defined(USE_AURA) || defined(OS_LINUX)
   {
     "overlay-scrollbars",
     IDS_FLAGS_ENABLE_OVERLAY_SCROLLBARS_NAME,
     IDS_FLAGS_ENABLE_OVERLAY_SCROLLBARS_DESCRIPTION,
     // Uses the system preference on Mac (a different implementation).
     // On Android, this is always enabled.
     kOsLinux | kOsCrOS | kOsWin,
     MULTI_VALUE_TYPE(kOverlayScrollbarChoices)
   },
 #endif
   {
     "enable-panels",
     IDS_FLAGS_ENABLE_PANELS_NAME,
     IDS_FLAGS_ENABLE_PANELS_DESCRIPTION,
     kOsDesktop,
-    SINGLE_VALUE_TYPE(switches::kEnablePanels)
+    SINGLE_VALUE_TYPE(switches::kEnablePanels,
+                      UMA_HISTOGRAM_ID_kEnablePanels)
   },
   {
     // See http://crbug.com/120416 for how to remove this flag.
     "save-page-as-mhtml",  // FLAGS:RECORD_UMA
     IDS_FLAGS_SAVE_PAGE_AS_MHTML_NAME,
     IDS_FLAGS_SAVE_PAGE_AS_MHTML_DESCRIPTION,
     kOsMac | kOsWin | kOsLinux,
-    SINGLE_VALUE_TYPE(switches::kSavePageAsMHTML)
+    SINGLE_VALUE_TYPE(switches::kSavePageAsMHTML,
+                      UMA_HISTOGRAM_ID_kSavePageAsMHTML)
   },
   {
     "enable-quic",
     IDS_FLAGS_ENABLE_QUIC_NAME,
     IDS_FLAGS_ENABLE_QUIC_DESCRIPTION,
     kOsAll,
     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableQuic,
-                              switches::kDisableQuic)
+                              UMA_HISTOGRAM_ID_kEnableQuic,
+                              switches::kDisableQuic,
+                              UMA_HISTOGRAM_ID_kDisableQuic)
   },
   {
     "enable-quic-https",
     IDS_FLAGS_ENABLE_QUIC_HTTPS_NAME,
     IDS_FLAGS_ENABLE_QUIC_HTTPS_DESCRIPTION,
     kOsAll,
     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableQuicHttps,
-                              switches::kDisableQuicHttps)
+                              UMA_HISTOGRAM_ID_kEnableQuicHttps,
+                              switches::kDisableQuicHttps,
+                              UMA_HISTOGRAM_ID_kDisableQuicHttps)
   },
   {
     "enable-spdy4",
     IDS_FLAGS_ENABLE_SPDY4_NAME,
     IDS_FLAGS_ENABLE_SPDY4_DESCRIPTION,
     kOsAll,
-    SINGLE_VALUE_TYPE(switches::kEnableSpdy4)
+    SINGLE_VALUE_TYPE(switches::kEnableSpdy4, UMA_HISTOGRAM_ID_kEnableSpdy4)
   },
   {
     "enable-async-dns",
     IDS_FLAGS_ENABLE_ASYNC_DNS_NAME,
     IDS_FLAGS_ENABLE_ASYNC_DNS_DESCRIPTION,
     kOsWin | kOsMac | kOsLinux | kOsCrOS,
     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableAsyncDns,
-                              switches::kDisableAsyncDns)
+                              UMA_HISTOGRAM_ID_kEnableAsyncDns,
+                              switches::kDisableAsyncDns,
+                              UMA_HISTOGRAM_ID_kDisableAsyncDns)
   },
   {
     "disable-media-source",
     IDS_FLAGS_DISABLE_MEDIA_SOURCE_NAME,
     IDS_FLAGS_DISABLE_MEDIA_SOURCE_DESCRIPTION,
     kOsAll,
-    SINGLE_VALUE_TYPE(switches::kDisableMediaSource)
+    SINGLE_VALUE_TYPE(switches::kDisableMediaSource,
+                      UMA_HISTOGRAM_ID_kDisableMediaSource)
   },
   {
     "enable-encrypted-media",
     IDS_FLAGS_ENABLE_ENCRYPTED_MEDIA_NAME,
     IDS_FLAGS_ENABLE_ENCRYPTED_MEDIA_DESCRIPTION,
     kOsAll,
-    SINGLE_VALUE_TYPE(switches::kEnableEncryptedMedia)
+    SINGLE_VALUE_TYPE(switches::kEnableEncryptedMedia,
+                      UMA_HISTOGRAM_ID_kEnableEncryptedMedia)
   },
   {
     "disable-prefixed-encrypted-media",
     IDS_FLAGS_DISABLE_PREFIXED_ENCRYPTED_MEDIA_NAME,
     IDS_FLAGS_DISABLE_PREFIXED_ENCRYPTED_MEDIA_DESCRIPTION,
     kOsAll,
-    SINGLE_VALUE_TYPE(switches::kDisablePrefixedEncryptedMedia)
+    SINGLE_VALUE_TYPE(switches::kDisablePrefixedEncryptedMedia,
+                      UMA_HISTOGRAM_ID_kDisablePrefixedEncryptedMedia)
   },
 #if defined(OS_ANDROID)
   {
     "disable-infobar-for-protected-media-identifier",
     IDS_FLAGS_DISABLE_INFOBAR_FOR_PROTECTED_MEDIA_IDENTIFIER_NAME,
     IDS_FLAGS_DISABLE_INFOBAR_FOR_PROTECTED_MEDIA_IDENTIFIER_DESCRIPTION,
     kOsAndroid,
-    SINGLE_VALUE_TYPE(switches::kDisableInfobarForProtectedMediaIdentifier)
+    SINGLE_VALUE_TYPE(
+        switches::kDisableInfobarForProtectedMediaIdentifier,
+        UMA_HISTOGRAM_ID_kDisableInfobarForProtectedMediaIdentifier)
   },
   {
     "mediadrm-enable-non-compositing",
     IDS_FLAGS_MEDIADRM_ENABLE_NON_COMPOSITING_NAME,
     IDS_FLAGS_MEDIADRM_ENABLE_NON_COMPOSITING_DESCRIPTION,
     kOsAndroid,
-    SINGLE_VALUE_TYPE(switches::kMediaDrmEnableNonCompositing)
+    SINGLE_VALUE_TYPE(switches::kMediaDrmEnableNonCompositing,
+                      UMA_HISTOGRAM_ID_kMediaDrmEnableNonCompositing)
   },
 #endif  // defined(OS_ANDROID)
   {
     "enable-javascript-harmony",
     IDS_FLAGS_ENABLE_JAVASCRIPT_HARMONY_NAME,
     IDS_FLAGS_ENABLE_JAVASCRIPT_HARMONY_DESCRIPTION,
     kOsAll,
-    SINGLE_VALUE_TYPE_AND_VALUE(switches::kJavaScriptFlags, "--harmony")
+    SINGLE_VALUE_TYPE_AND_VALUE(switches::kJavaScriptFlags,
+                                "--harmony",
+                                UMA_HISTOGRAM_ID_kJavaScriptFlags)
   },
   {
     "disable-software-rasterizer",
     IDS_FLAGS_DISABLE_SOFTWARE_RASTERIZER_NAME,
     IDS_FLAGS_DISABLE_SOFTWARE_RASTERIZER_DESCRIPTION,
 #if defined(ENABLE_SWIFTSHADER)
     kOsAll,
 #else
     0,
 #endif
-    SINGLE_VALUE_TYPE(switches::kDisableSoftwareRasterizer)
+    SINGLE_VALUE_TYPE(switches::kDisableSoftwareRasterizer,
+                      UMA_HISTOGRAM_ID_kDisableSoftwareRasterizer)
   },
   {
     "enable-gpu-rasterization",
     IDS_FLAGS_ENABLE_GPU_RASTERIZATION_NAME,
     IDS_FLAGS_ENABLE_GPU_RASTERIZATION_DESCRIPTION,
     kOsAndroid,
     MULTI_VALUE_TYPE(kEnableGpuRasterizationChoices)
   },
   {
     "enable-experimental-web-platform-features",
     IDS_FLAGS_EXPERIMENTAL_WEB_PLATFORM_FEATURES_NAME,
     IDS_FLAGS_EXPERIMENTAL_WEB_PLATFORM_FEATURES_DESCRIPTION,
     kOsAll,
-    SINGLE_VALUE_TYPE(switches::kEnableExperimentalWebPlatformFeatures)
+    SINGLE_VALUE_TYPE(
+        switches::kEnableExperimentalWebPlatformFeatures,
+        UMA_HISTOGRAM_ID_kEnableExperimentalWebPlatformFeatures)
   },
   {
     "disable-ntp-other-sessions-menu",
     IDS_FLAGS_NTP_OTHER_SESSIONS_MENU_NAME,
     IDS_FLAGS_NTP_OTHER_SESSIONS_MENU_DESCRIPTION,
     kOsDesktop,
-    SINGLE_VALUE_TYPE(switches::kDisableNTPOtherSessionsMenu)
+    SINGLE_VALUE_TYPE(switches::kDisableNTPOtherSessionsMenu,
+                      UMA_HISTOGRAM_ID_kDisableNTPOtherSessionsMenu)
   },
   {
     "enable-devtools-experiments",
     IDS_FLAGS_ENABLE_DEVTOOLS_EXPERIMENTS_NAME,
     IDS_FLAGS_ENABLE_DEVTOOLS_EXPERIMENTS_DESCRIPTION,
     kOsDesktop,
-    SINGLE_VALUE_TYPE(switches::kEnableDevToolsExperiments)
+    SINGLE_VALUE_TYPE(switches::kEnableDevToolsExperiments,
+                      UMA_HISTOGRAM_ID_kEnableDevToolsExperiments)
   },
   {
     "silent-debugger-extension-api",
     IDS_FLAGS_SILENT_DEBUGGER_EXTENSION_API_NAME,
     IDS_FLAGS_SILENT_DEBUGGER_EXTENSION_API_DESCRIPTION,
     kOsDesktop,
-    SINGLE_VALUE_TYPE(switches::kSilentDebuggerExtensionAPI)
+    SINGLE_VALUE_TYPE(switches::kSilentDebuggerExtensionAPI,
+                      UMA_HISTOGRAM_ID_kSilentDebuggerExtensionAPI)
   },
   {
     "spellcheck-autocorrect",
     IDS_FLAGS_SPELLCHECK_AUTOCORRECT,
     IDS_FLAGS_SPELLCHECK_AUTOCORRECT_DESCRIPTION,
     kOsWin | kOsLinux | kOsCrOS,
-    SINGLE_VALUE_TYPE(switches::kEnableSpellingAutoCorrect)
+    SINGLE_VALUE_TYPE(switches::kEnableSpellingAutoCorrect,
+                      UMA_HISTOGRAM_ID_kEnableSpellingAutoCorrect)
   },
   {
     "enable-scroll-prediction",
     IDS_FLAGS_ENABLE_SCROLL_PREDICTION_NAME,
     IDS_FLAGS_ENABLE_SCROLL_PREDICTION_DESCRIPTION,
     kOsDesktop,
-    SINGLE_VALUE_TYPE(switches::kEnableScrollPrediction)
+    SINGLE_VALUE_TYPE(switches::kEnableScrollPrediction,
+                      UMA_HISTOGRAM_ID_kEnableScrollPrediction)
   },
   {
     "touch-events",
     IDS_TOUCH_EVENTS_NAME,
     IDS_TOUCH_EVENTS_DESCRIPTION,
-    kOsDesktop,
-    MULTI_VALUE_TYPE(kTouchEventsChoices)
+    kOsDesktop, MULTI_VALUE_TYPE(kTouchEventsChoices)
   },
   {
     "disable-touch-adjustment",
     IDS_DISABLE_TOUCH_ADJUSTMENT_NAME,
     IDS_DISABLE_TOUCH_ADJUSTMENT_DESCRIPTION,
     kOsWin | kOsLinux | kOsCrOS,
-    SINGLE_VALUE_TYPE(switches::kDisableTouchAdjustment)
+    SINGLE_VALUE_TYPE(switches::kDisableTouchAdjustment,
+                      UMA_HISTOGRAM_ID_kDisableTouchAdjustment)
   },
 #if defined(OS_CHROMEOS)
   {
     "network-portal-notification",
     IDS_FLAGS_NETWORK_PORTAL_NOTIFICATION_NAME,
     IDS_FLAGS_NETWORK_PORTAL_NOTIFICATION_DESCRIPTION,
     kOsCrOS,
     ENABLE_DISABLE_VALUE_TYPE(
         chromeos::switches::kEnableNetworkPortalNotification,
-        chromeos::switches::kDisableNetworkPortalNotification)
+        UMA_HISTOGRAM_ID_kEnableNetworkPortalNotification,
+        chromeos::switches::kDisableNetworkPortalNotification,
+        UMA_HISTOGRAM_ID_kDisableNetworkPortalNotification)
   },
 #endif
   {
     "enable-download-resumption",
     IDS_FLAGS_ENABLE_DOWNLOAD_RESUMPTION_NAME,
     IDS_FLAGS_ENABLE_DOWNLOAD_RESUMPTION_DESCRIPTION,
     kOsDesktop,
-    SINGLE_VALUE_TYPE(switches::kEnableDownloadResumption)
+    SINGLE_VALUE_TYPE(switches::kEnableDownloadResumption,
+                      UMA_HISTOGRAM_ID_kEnableDownloadResumption)
   },
   // Native client is compiled out when DISABLE_NACL is defined.
 #if !defined(DISABLE_NACL)
   {
     "allow-nacl-socket-api",
     IDS_FLAGS_ALLOW_NACL_SOCKET_API_NAME,
     IDS_FLAGS_ALLOW_NACL_SOCKET_API_DESCRIPTION,
     kOsDesktop,
-    SINGLE_VALUE_TYPE_AND_VALUE(switches::kAllowNaClSocketAPI, "*")
+    SINGLE_VALUE_TYPE_AND_VALUE(switches::kAllowNaClSocketAPI,
+                                "*",
+                                UMA_HISTOGRAM_ID_kAllowNaClSocketAPI)
   },
 #endif
   {
     "force-device-scale-factor",
     IDS_FLAGS_FORCE_HIGH_DPI_NAME,
     IDS_FLAGS_FORCE_HIGH_DPI_DESCRIPTION,
     kOsCrOS,
-    SINGLE_VALUE_TYPE_AND_VALUE(switches::kForceDeviceScaleFactor, "2")
+    SINGLE_VALUE_TYPE_AND_VALUE(switches::kForceDeviceScaleFactor,
+                                "2",
+                                UMA_HISTOGRAM_ID_kForceDeviceScaleFactor)
   },
 #if defined(OS_CHROMEOS)
   {
     "allow-touchpad-three-finger-click",
     IDS_FLAGS_ALLOW_TOUCHPAD_THREE_FINGER_CLICK_NAME,
     IDS_FLAGS_ALLOW_TOUCHPAD_THREE_FINGER_CLICK_DESCRIPTION,
     kOsCrOS,
-    SINGLE_VALUE_TYPE(chromeos::switches::kEnableTouchpadThreeFingerClick)
+    SINGLE_VALUE_TYPE(chromeos::switches::kEnableTouchpadThreeFingerClick,
+                      UMA_HISTOGRAM_ID_kEnableTouchpadThreeFingerClick)
   },
 #endif
 #if defined(USE_ASH)
   {
     "disable-minimize-on-second-launcher-item-click",
     IDS_FLAGS_DISABLE_MINIMIZE_ON_SECOND_LAUNCHER_ITEM_CLICK_NAME,
     IDS_FLAGS_DISABLE_MINIMIZE_ON_SECOND_LAUNCHER_ITEM_CLICK_DESCRIPTION,
     kOsAll,
-    SINGLE_VALUE_TYPE(switches::kDisableMinimizeOnSecondLauncherItemClick)
+    SINGLE_VALUE_TYPE(switches::kDisableMinimizeOnSecondLauncherItemClick,
+        UMA_HISTOGRAM_ID_kDisableMinimizeOnSecondLauncherItemClick)
   },
   {
     "show-touch-hud",
     IDS_FLAGS_SHOW_TOUCH_HUD_NAME,
     IDS_FLAGS_SHOW_TOUCH_HUD_DESCRIPTION,
     kOsAll,
-    SINGLE_VALUE_TYPE(ash::switches::kAshTouchHud)
+    SINGLE_VALUE_TYPE(ash::switches::kAshTouchHud,
+                      UMA_HISTOGRAM_ID_kAshTouchHud)
   },
   {
     "enable-pinch",
     IDS_FLAGS_ENABLE_PINCH_SCALE_NAME,
     IDS_FLAGS_ENABLE_PINCH_SCALE_DESCRIPTION,
     kOsLinux | kOsWin | kOsCrOS,
-    ENABLE_DISABLE_VALUE_TYPE(switches::kEnablePinch, switches::kDisablePinch),
+    ENABLE_DISABLE_VALUE_TYPE(switches::kEnablePinch,
+                              UMA_HISTOGRAM_ID_kEnablePinch,
+                              switches::kDisablePinch,
+                              UMA_HISTOGRAM_ID_kDisablePinch)
   },
 #endif  // defined(USE_ASH)
   {
     "enable-pinch-virtual-viewport",
     IDS_FLAGS_ENABLE_PINCH_VIRTUAL_VIEWPORT_NAME,
     IDS_FLAGS_ENABLE_PINCH_VIRTUAL_VIEWPORT_DESCRIPTION,
     kOsLinux | kOsWin | kOsCrOS | kOsAndroid,
-    ENABLE_DISABLE_VALUE_TYPE(
-        cc::switches::kEnablePinchVirtualViewport,
-        cc::switches::kDisablePinchVirtualViewport),
+    ENABLE_DISABLE_VALUE_TYPE(cc::switches::kEnablePinchVirtualViewport,
+                              UMA_HISTOGRAM_ID_kEnablePinchVirtualViewport,
+                              cc::switches::kDisablePinchVirtualViewport,
+                              UMA_HISTOGRAM_ID_kDisablePinchVirtualViewport)
   },
   {
     "enable-viewport-meta",
     IDS_FLAGS_ENABLE_VIEWPORT_META_NAME,
     IDS_FLAGS_ENABLE_VIEWPORT_META_DESCRIPTION,
     kOsLinux | kOsWin | kOsCrOS | kOsMac,
-    SINGLE_VALUE_TYPE(switches::kEnableViewportMeta),
+    SINGLE_VALUE_TYPE(switches::kEnableViewportMeta,
+                      UMA_HISTOGRAM_ID_kEnableViewportMeta)
   },
 #if defined(OS_CHROMEOS)
   {
     "disable-boot-animation",
     IDS_FLAGS_DISABLE_BOOT_ANIMATION,
     IDS_FLAGS_DISABLE_BOOT_ANIMATION_DESCRIPTION,
     kOsCrOSOwnerOnly,
-    SINGLE_VALUE_TYPE(chromeos::switches::kDisableBootAnimation),
+    SINGLE_VALUE_TYPE(chromeos::switches::kDisableBootAnimation,
+                      UMA_HISTOGRAM_ID_kDisableBootAnimation)
   },
   {
     "enable-new-audio-player",
     IDS_FLAGS_FILE_MANAGER_ENABLE_NEW_AUDIO_PLAYER_NAME,
     IDS_FLAGS_FILE_MANAGER_ENABLE_NEW_AUDIO_PLAYER_DESCRIPTION,
     kOsCrOS,
-    SINGLE_VALUE_TYPE(chromeos::switches::kFileManagerEnableNewAudioPlayer)
+    SINGLE_VALUE_TYPE(chromeos::switches::kFileManagerEnableNewAudioPlayer,
+                      UMA_HISTOGRAM_ID_kFileManagerEnableNewAudioPlayer)
   },
   {
     "enable-new-gallery",
     IDS_FLAGS_FILE_MANAGER_ENABLE_NEW_GALLERY_NAME,
     IDS_FLAGS_FILE_MANAGER_ENABLE_NEW_GALLERY_DESCRIPTION,
     kOsCrOS,
     MULTI_VALUE_TYPE(kEnableFileManagerNewGalleryChoices)
   },
   {
     "disable-quickoffice-component-app",
     IDS_FLAGS_DISABLE_QUICKOFFICE_COMPONENT_APP_NAME,
     IDS_FLAGS_DISABLE_QUICKOFFICE_COMPONENT_APP_DESCRIPTION,
     kOsCrOS,
-    SINGLE_VALUE_TYPE(chromeos::switches::kDisableQuickofficeComponentApp),
+    SINGLE_VALUE_TYPE(chromeos::switches::kDisableQuickofficeComponentApp,
+                      UMA_HISTOGRAM_ID_kDisableQuickofficeComponentApp)
   },
   {
     "disable-saml-signin",
     IDS_FLAGS_DISABLE_SAML_SIGNIN_NAME,
     IDS_FLAGS_DISABLE_SAML_SIGNIN_DESCRIPTION,
     kOsCrOS,
-    SINGLE_VALUE_TYPE(chromeos::switches::kDisableSamlSignin),
+    SINGLE_VALUE_TYPE(chromeos::switches::kDisableSamlSignin,
+                      UMA_HISTOGRAM_ID_kDisableSamlSignin)
   },
   {
     "disable-display-color-calibration",
     IDS_FLAGS_DISABLE_DISPLAY_COLOR_CALIBRATION_NAME,
     IDS_FLAGS_DISABLE_DISPLAY_COLOR_CALIBRATION_DESCRIPTION,
     kOsCrOS,
-    SINGLE_VALUE_TYPE(ui::switches::kDisableDisplayColorCalibration),
+    SINGLE_VALUE_TYPE(ui::switches::kDisableDisplayColorCalibration,
+                      UMA_HISTOGRAM_ID_kDisableDisplayColorCalibration)
   },
 #endif  // defined(OS_CHROMEOS)
-  { "disable-accelerated-video-decode",
+  {
+    "disable-accelerated-video-decode",
     IDS_FLAGS_DISABLE_ACCELERATED_VIDEO_DECODE_NAME,
     IDS_FLAGS_DISABLE_ACCELERATED_VIDEO_DECODE_DESCRIPTION,
     kOsWin | kOsCrOS,
-    SINGLE_VALUE_TYPE(switches::kDisableAcceleratedVideoDecode),
+    SINGLE_VALUE_TYPE(switches::kDisableAcceleratedVideoDecode,
+                      UMA_HISTOGRAM_ID_kDisableAcceleratedVideoDecode)
   },
 #if defined(USE_ASH)
   {
     "ash-debug-shortcuts",
     IDS_FLAGS_DEBUG_SHORTCUTS_NAME,
     IDS_FLAGS_DEBUG_SHORTCUTS_DESCRIPTION,
     kOsAll,
-    SINGLE_VALUE_TYPE(ash::switches::kAshDebugShortcuts),
+    SINGLE_VALUE_TYPE(ash::switches::kAshDebugShortcuts,
+                      UMA_HISTOGRAM_ID_kAshDebugShortcuts)
   },
-  { "ash-enable-touch-view-testing",
+  {
+    "ash-enable-touch-view-testing",
     IDS_FLAGS_ASH_ENABLE_TOUCH_VIEW_TESTING_NAME,
     IDS_FLAGS_ASH_ENABLE_TOUCH_VIEW_TESTING_DESCRIPTION,
     kOsCrOS,
-    SINGLE_VALUE_TYPE(ash::switches::kAshEnableTouchViewTesting),
+    SINGLE_VALUE_TYPE(ash::switches::kAshEnableTouchViewTesting,
+                      UMA_HISTOGRAM_ID_kAshEnableTouchViewTesting)
   },
 #endif
 #if defined(OS_CHROMEOS)
   {
     "enable-carrier-switching",
     IDS_FLAGS_ENABLE_CARRIER_SWITCHING,
     IDS_FLAGS_ENABLE_CARRIER_SWITCHING_DESCRIPTION,
     kOsCrOS,
-    SINGLE_VALUE_TYPE(chromeos::switches::kEnableCarrierSwitching)
+    SINGLE_VALUE_TYPE(chromeos::switches::kEnableCarrierSwitching,
+                      UMA_HISTOGRAM_ID_kEnableCarrierSwitching)
   },
   {
     "enable-request-tablet-site",
     IDS_FLAGS_ENABLE_REQUEST_TABLET_SITE_NAME,
     IDS_FLAGS_ENABLE_REQUEST_TABLET_SITE_DESCRIPTION,
     kOsCrOS,
-    SINGLE_VALUE_TYPE(chromeos::switches::kEnableRequestTabletSite)
+    SINGLE_VALUE_TYPE(chromeos::switches::kEnableRequestTabletSite,
+                      UMA_HISTOGRAM_ID_kEnableRequestTabletSite)
   },
 #endif
   {
     "debug-packed-apps",
     IDS_FLAGS_DEBUG_PACKED_APP_NAME,
     IDS_FLAGS_DEBUG_PACKED_APP_DESCRIPTION,
     kOsDesktop,
-    SINGLE_VALUE_TYPE(switches::kDebugPackedApps)
+    SINGLE_VALUE_TYPE(switches::kDebugPackedApps,
+                      UMA_HISTOGRAM_ID_kDebugPackedApps)
   },
   {
     "enable-password-generation",
     IDS_FLAGS_ENABLE_PASSWORD_GENERATION_NAME,
     IDS_FLAGS_ENABLE_PASSWORD_GENERATION_DESCRIPTION,
     kOsDesktop,
     ENABLE_DISABLE_VALUE_TYPE(autofill::switches::kEnablePasswordGeneration,
-                              autofill::switches::kDisablePasswordGeneration)
+                              UMA_HISTOGRAM_ID_kEnablePasswordGeneration,
+                              autofill::switches::kDisablePasswordGeneration,
+                              UMA_HISTOGRAM_ID_kDisablePasswordGeneration)
   },
   {
     "enable-automatic-password-saving",
     IDS_FLAGS_ENABLE_AUTOMATIC_PASSWORD_SAVING_NAME,
     IDS_FLAGS_ENABLE_AUTOMATIC_PASSWORD_SAVING_DESCRIPTION,
     kOsDesktop,
     SINGLE_VALUE_TYPE(
-        password_manager::switches::kEnableAutomaticPasswordSaving)
+        password_manager::switches::kEnableAutomaticPasswordSaving,
+        UMA_HISTOGRAM_ID_kEnableAutomaticPasswordSaving)
   },
   {
     "password-manager-reauthentication",
     IDS_FLAGS_PASSWORD_MANAGER_REAUTHENTICATION_NAME,
     IDS_FLAGS_PASSWORD_MANAGER_REAUTHENTICATION_DESCRIPTION,
     kOsMac | kOsWin,
-    SINGLE_VALUE_TYPE(switches::kDisablePasswordManagerReauthentication)
+    SINGLE_VALUE_TYPE(
+        switches::kDisablePasswordManagerReauthentication,
+        UMA_HISTOGRAM_ID_kDisablePasswordManagerReauthentication)
   },
   {
     "enable-deferred-image-decoding",
     IDS_FLAGS_ENABLE_DEFERRED_IMAGE_DECODING_NAME,
     IDS_FLAGS_ENABLE_DEFERRED_IMAGE_DECODING_DESCRIPTION,
     kOsMac | kOsLinux | kOsCrOS,
-    SINGLE_VALUE_TYPE(switches::kEnableDeferredImageDecoding)
+    SINGLE_VALUE_TYPE(switches::kEnableDeferredImageDecoding,
+                      UMA_HISTOGRAM_ID_kEnableDeferredImageDecoding)
   },
   {
     "performance-monitor-gathering",
     IDS_FLAGS_PERFORMANCE_MONITOR_GATHERING_NAME,
     IDS_FLAGS_PERFORMANCE_MONITOR_GATHERING_DESCRIPTION,
     kOsAll,
-    SINGLE_VALUE_TYPE(switches::kPerformanceMonitorGathering)
+    SINGLE_VALUE_TYPE(switches::kPerformanceMonitorGathering,
+                      UMA_HISTOGRAM_ID_kPerformanceMonitorGathering)
   },
   {
     "wallet-service-use-sandbox",
     IDS_FLAGS_WALLET_SERVICE_USE_SANDBOX_NAME,
     IDS_FLAGS_WALLET_SERVICE_USE_SANDBOX_DESCRIPTION,
     kOsAndroid | kOsDesktop,
     ENABLE_DISABLE_VALUE_TYPE_AND_VALUE(
         autofill::switches::kWalletServiceUseSandbox, "1",
-        autofill::switches::kWalletServiceUseSandbox, "0")
+        UMA_HISTOGRAM_ID_kWalletServiceUseSandbox,
+        autofill::switches::kWalletServiceUseSandbox, "0",
+        UMA_HISTOGRAM_ID_kWalletServiceUseSandbox)
   },
 #if defined(USE_AURA)
   {
     "overscroll-history-navigation",
     IDS_FLAGS_OVERSCROLL_HISTORY_NAVIGATION_NAME,
     IDS_FLAGS_OVERSCROLL_HISTORY_NAVIGATION_DESCRIPTION,
     kOsAll,
     MULTI_VALUE_TYPE(kOverscrollHistoryNavigationChoices)
   },
 #endif
   {
     "scroll-end-effect",
     IDS_FLAGS_SCROLL_END_EFFECT_NAME,
     IDS_FLAGS_SCROLL_END_EFFECT_DESCRIPTION,
     kOsCrOS,
     ENABLE_DISABLE_VALUE_TYPE_AND_VALUE(
         switches::kScrollEndEffect, "1",
-        switches::kScrollEndEffect, "0")
+        UMA_HISTOGRAM_ID_kScrollEndEffect,
+        switches::kScrollEndEffect, "0",
+        UMA_HISTOGRAM_ID_kScrollEndEffect)
   },
   {
     "enable-touch-drag-drop",
     IDS_FLAGS_ENABLE_TOUCH_DRAG_DROP_NAME,
     IDS_FLAGS_ENABLE_TOUCH_DRAG_DROP_DESCRIPTION,
     kOsWin | kOsCrOS,
     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableTouchDragDrop,
-                              switches::kDisableTouchDragDrop)
+                              UMA_HISTOGRAM_ID_kEnableTouchDragDrop,
+                              switches::kDisableTouchDragDrop,
+                              UMA_HISTOGRAM_ID_kDisableTouchDragDrop)
   },
   {
     "enable-touch-editing",
     IDS_FLAGS_ENABLE_TOUCH_EDITING_NAME,
     IDS_FLAGS_ENABLE_TOUCH_EDITING_DESCRIPTION,
     kOsCrOS | kOsWin | kOsLinux,
     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableTouchEditing,
-                              switches::kDisableTouchEditing)
+                              UMA_HISTOGRAM_ID_kEnableTouchEditing,
+                              switches::kDisableTouchEditing,
+                              UMA_HISTOGRAM_ID_kDisableTouchEditing)
   },
   {
     "enable-suggestions-service",
     IDS_FLAGS_ENABLE_SUGGESTIONS_SERVICE_NAME,
     IDS_FLAGS_ENABLE_SUGGESTIONS_SERVICE_DESCRIPTION,
     kOsAndroid | kOsCrOS,
     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableSuggestionsService,
-                              switches::kDisableSuggestionsService)
+                              UMA_HISTOGRAM_ID_kEnableSuggestionsService,
+                              switches::kDisableSuggestionsService,
+                              UMA_HISTOGRAM_ID_kDisableSuggestionsService)
   },
   {
     "enable-sync-synced-notifications",
     IDS_FLAGS_ENABLE_SYNCED_NOTIFICATIONS_NAME,
     IDS_FLAGS_ENABLE_SYNCED_NOTIFICATIONS_DESCRIPTION,
     kOsDesktop,
-    ENABLE_DISABLE_VALUE_TYPE(switches::kEnableSyncSyncedNotifications,
-                              switches::kDisableSyncSyncedNotifications)
+    ENABLE_DISABLE_VALUE_TYPE(
+        switches::kEnableSyncSyncedNotifications,
+        UMA_HISTOGRAM_ID_kEnableSyncSyncedNotifications,
+        switches::kDisableSyncSyncedNotifications,
+        UMA_HISTOGRAM_ID_kDisableSyncSyncedNotifications)
   },
 #if defined(ENABLE_APP_LIST)
   {
     "enable-sync-app-list",
     IDS_FLAGS_ENABLE_SYNC_APP_LIST_NAME,
     IDS_FLAGS_ENABLE_SYNC_APP_LIST_DESCRIPTION,
     kOsDesktop,
     MULTI_VALUE_TYPE(kEnableSyncAppListChoices)
   },
 #endif
 #if defined(OS_MACOSX)
   {
     "enable-avfoundation",
     IDS_FLAGS_ENABLE_AVFOUNDATION_NAME,
     IDS_FLAGS_ENABLE_AVFOUNDATION_DESCRIPTION,
     kOsMac,
-    SINGLE_VALUE_TYPE(switches::kEnableAVFoundation)
+    SINGLE_VALUE_TYPE(switches::kEnableAVFoundation,
+                      UMA_HISTOGRAM_ID_kEnableAVFoundation)
   },
 #endif
   {
     "impl-side-painting",
     IDS_FLAGS_IMPL_SIDE_PAINTING_NAME,
     IDS_FLAGS_IMPL_SIDE_PAINTING_DESCRIPTION,
     kOsAll,
     MULTI_VALUE_TYPE(kImplSidePaintingChoices)
   },
   {
@@ skipping 18 matching lines @@
     IDS_FLAGS_MAX_TILES_FOR_INTEREST_AREA_DESCRIPTION,
     kOsAll,
     MULTI_VALUE_TYPE(kMaxTilesForInterestAreaChoices)
   },
   {
     "enable-offline-auto-reload",
     IDS_FLAGS_ENABLE_OFFLINE_AUTO_RELOAD_NAME,
     IDS_FLAGS_ENABLE_OFFLINE_AUTO_RELOAD_DESCRIPTION,
     kOsAll,
     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableOfflineAutoReload,
-                              switches::kDisableOfflineAutoReload)
+                              UMA_HISTOGRAM_ID_kEnableOfflineAutoReload,
+                              switches::kDisableOfflineAutoReload,
+                              UMA_HISTOGRAM_ID_kDisableOfflineAutoReload)
   },
   {
     "enable-offline-auto-reload-visible-only",
     IDS_FLAGS_ENABLE_OFFLINE_AUTO_RELOAD_VISIBLE_ONLY_NAME,
     IDS_FLAGS_ENABLE_OFFLINE_AUTO_RELOAD_VISIBLE_ONLY_DESCRIPTION,
     kOsAll,
-    ENABLE_DISABLE_VALUE_TYPE(switches::kEnableOfflineAutoReloadVisibleOnly,
-                              switches::kDisableOfflineAutoReloadVisibleOnly)
+    ENABLE_DISABLE_VALUE_TYPE(
+        switches::kEnableOfflineAutoReloadVisibleOnly,
+        UMA_HISTOGRAM_ID_kEnableOfflineAutoReloadVisibleOnly,
+        switches::kDisableOfflineAutoReloadVisibleOnly,
+        UMA_HISTOGRAM_ID_kDisableOfflineAutoReloadVisibleOnly)
   },
   {
     "enable-offline-load-stale-cache",
     IDS_FLAGS_ENABLE_OFFLINE_LOAD_STALE_NAME,
     IDS_FLAGS_ENABLE_OFFLINE_LOAD_STALE_DESCRIPTION,
     kOsLinux | kOsMac | kOsWin | kOsAndroid,
     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableOfflineLoadStaleCache,
-                              switches::kDisableOfflineLoadStaleCache)
+                              UMA_HISTOGRAM_ID_kEnableOfflineLoadStaleCache,
+                              switches::kDisableOfflineLoadStaleCache,
+                              UMA_HISTOGRAM_ID_kDisableOfflineLoadStaleCache)
   },
   {
     "default-tile-width",
     IDS_FLAGS_DEFAULT_TILE_WIDTH_NAME,
     IDS_FLAGS_DEFAULT_TILE_WIDTH_DESCRIPTION,
     kOsAll,
     MULTI_VALUE_TYPE(kDefaultTileWidthChoices)
   },
   {
     "default-tile-height",
     IDS_FLAGS_DEFAULT_TILE_HEIGHT_NAME,
     IDS_FLAGS_DEFAULT_TILE_HEIGHT_DESCRIPTION,
     kOsAll,
     MULTI_VALUE_TYPE(kDefaultTileHeightChoices)
   },
 #if defined(OS_ANDROID)
   {
     "disable-gesture-requirement-for-media-playback",
     IDS_FLAGS_DISABLE_GESTURE_REQUIREMENT_FOR_MEDIA_PLAYBACK_NAME,
     IDS_FLAGS_DISABLE_GESTURE_REQUIREMENT_FOR_MEDIA_PLAYBACK_DESCRIPTION,
     kOsAndroid,
-    SINGLE_VALUE_TYPE(switches::kDisableGestureRequirementForMediaPlayback)
+    SINGLE_VALUE_TYPE(
+        switches::kDisableGestureRequirementForMediaPlayback,
+        UMA_HISTOGRAM_ID_kDisableGestureRequirementForMediaPlayback)
   },
 #endif
 #if defined(OS_CHROMEOS)
   {
     "enable-virtual-keyboard",
     IDS_FLAGS_ENABLE_VIRTUAL_KEYBOARD_NAME,
     IDS_FLAGS_ENABLE_VIRTUAL_KEYBOARD_DESCRIPTION,
     kOsCrOS,
-    SINGLE_VALUE_TYPE(keyboard::switches::kEnableVirtualKeyboard)
+    SINGLE_VALUE_TYPE(keyboard::switches::kEnableVirtualKeyboard,
+                      UMA_HISTOGRAM_ID_kEnableVirtualKeyboard)
   },
   {
     "enable-virtual-keyboard-overscroll",
     IDS_FLAGS_ENABLE_VIRTUAL_KEYBOARD_OVERSCROLL_NAME,
     IDS_FLAGS_ENABLE_VIRTUAL_KEYBOARD_OVERSCROLL_DESCRIPTION,
     kOsCrOS,
     ENABLE_DISABLE_VALUE_TYPE(
         keyboard::switches::kEnableVirtualKeyboardOverscroll,
-        keyboard::switches::kDisableVirtualKeyboardOverscroll)
+        UMA_HISTOGRAM_ID_kEnableVirtualKeyboardOverscroll,
+        keyboard::switches::kDisableVirtualKeyboardOverscroll,
+        UMA_HISTOGRAM_ID_kDisableVirtualKeyboardOverscroll)
   },
   {
     "enable-swipe-selection",
     IDS_FLAGS_ENABLE_SWIPE_SELECTION_NAME,
     IDS_FLAGS_ENABLE_SWIPE_SELECTION_DESCRIPTION,
     kOsCrOS,
-    SINGLE_VALUE_TYPE(keyboard::switches::kEnableSwipeSelection)
+    SINGLE_VALUE_TYPE(keyboard::switches::kEnableSwipeSelection,
+                      UMA_HISTOGRAM_ID_kEnableSwipeSelection)
   },
   {
     "enable-input-view",
     IDS_FLAGS_ENABLE_INPUT_VIEW_NAME,
     IDS_FLAGS_ENABLE_INPUT_VIEW_DESCRIPTION,
     kOsCrOS,
     ENABLE_DISABLE_VALUE_TYPE(keyboard::switches::kEnableInputView,
-                              keyboard::switches::kDisableInputView)
+                              UMA_HISTOGRAM_ID_kEnableInputView,
+                              keyboard::switches::kDisableInputView,
+                              UMA_HISTOGRAM_ID_kDisableInputView)
   },
   {
     "enable-experimental-input-view-features",
     IDS_FLAGS_ENABLE_EXPERIMENTAL_INPUT_VIEW_FEATURES_NAME,
     IDS_FLAGS_ENABLE_EXPERIMENTAL_INPUT_VIEW_FEATURES_DESCRIPTION,
     kOsCrOS,
-    SINGLE_VALUE_TYPE(keyboard::switches::kEnableExperimentalInputViewFeatures)
+    SINGLE_VALUE_TYPE(keyboard::switches::kEnableExperimentalInputViewFeatures,
+                      UMA_HISTOGRAM_ID_kEnableExperimentalInputViewFeatures)
   },
 #endif
   {
     "enable-simple-cache-backend",
     IDS_FLAGS_ENABLE_SIMPLE_CACHE_BACKEND_NAME,
     IDS_FLAGS_ENABLE_SIMPLE_CACHE_BACKEND_DESCRIPTION,
     kOsWin | kOsMac | kOsLinux | kOsCrOS,
     MULTI_VALUE_TYPE(kSimpleCacheBackendChoices)
   },
   {
     "enable-tcp-fast-open",
     IDS_FLAGS_ENABLE_TCP_FAST_OPEN_NAME,
     IDS_FLAGS_ENABLE_TCP_FAST_OPEN_DESCRIPTION,
     kOsLinux | kOsCrOS | kOsAndroid,
-    SINGLE_VALUE_TYPE(switches::kEnableTcpFastOpen)
+    SINGLE_VALUE_TYPE(switches::kEnableTcpFastOpen,
+                      UMA_HISTOGRAM_ID_kEnableTcpFastOpen)
   },
   {
     "enable-syncfs-directory-operation",
     IDS_FLAGS_ENABLE_SYNC_DIRECTORY_OPERATION_NAME,
     IDS_FLAGS_ENABLE_SYNC_DIRECTORY_OPERATION_DESCRIPTION,
     kOsAll,
-    SINGLE_VALUE_TYPE(switches::kSyncfsEnableDirectoryOperation),
+    SINGLE_VALUE_TYPE(switches::kSyncfsEnableDirectoryOperation,
+                      UMA_HISTOGRAM_ID_kSyncfsEnableDirectoryOperation)
   },
 #if defined(ENABLE_SERVICE_DISCOVERY)
   {
     "disable-device-discovery",
     IDS_FLAGS_DISABLE_DEVICE_DISCOVERY_NAME,
     IDS_FLAGS_DISABLE_DEVICE_DISCOVERY_DESCRIPTION,
     kOsDesktop,
-    SINGLE_VALUE_TYPE(switches::kDisableDeviceDiscovery)
+    SINGLE_VALUE_TYPE(switches::kDisableDeviceDiscovery,
+                      UMA_HISTOGRAM_ID_kDisableDeviceDiscovery)
   },
   {
     "device-discovery-notifications",
     IDS_FLAGS_DEVICE_DISCOVERY_NOTIFICATIONS_NAME,
     IDS_FLAGS_DEVICE_DISCOVERY_NOTIFICATIONS_DESCRIPTION,
     kOsDesktop,
-    ENABLE_DISABLE_VALUE_TYPE(switches::kEnableDeviceDiscoveryNotifications,
-                              switches::kDisableDeviceDiscoveryNotifications)
+    ENABLE_DISABLE_VALUE_TYPE(
+        switches::kEnableDeviceDiscoveryNotifications,
+        UMA_HISTOGRAM_ID_kEnableDeviceDiscoveryNotifications,
+        switches::kDisableDeviceDiscoveryNotifications,
+        UMA_HISTOGRAM_ID_kDisableDeviceDiscoveryNotifications)
   },
   {
     "enable-cloud-devices",
     IDS_FLAGS_ENABLE_CLOUD_DEVICES_NAME,
     IDS_FLAGS_ENABLE_CLOUD_DEVICES_DESCRIPTION,
     kOsDesktop,
-    SINGLE_VALUE_TYPE(switches::kEnableCloudDevices)
+    SINGLE_VALUE_TYPE(switches::kEnableCloudDevices,
+                      UMA_HISTOGRAM_ID_kEnableCloudDevices)
   },
   {
     "enable-print-preview-register-promos",
     IDS_FLAGS_ENABLE_PRINT_PREVIEW_REGISTER_PROMOS_NAME,
     IDS_FLAGS_ENABLE_PRINT_PREVIEW_REGISTER_PROMOS_DESCRIPTION,
     kOsDesktop,
-    SINGLE_VALUE_TYPE(switches::kEnablePrintPreviewRegisterPromos)
+    SINGLE_VALUE_TYPE(switches::kEnablePrintPreviewRegisterPromos,
+                      UMA_HISTOGRAM_ID_kEnablePrintPreviewRegisterPromos)
   },
 #endif  // ENABLE_SERVICE_DISCOVERY
 #if defined(OS_WIN)
   {
     "enable-cloud-print-xps",
     IDS_FLAGS_ENABLE_CLOUD_PRINT_XPS_NAME,
     IDS_FLAGS_ENABLE_CLOUD_PRINT_XPS_DESCRIPTION,
     kOsWin,
-    SINGLE_VALUE_TYPE(switches::kEnableCloudPrintXps)
+    SINGLE_VALUE_TYPE(switches::kEnableCloudPrintXps,
+                      UMA_HISTOGRAM_ID_kEnableCloudPrintXps)
   },
 #endif
 #if defined(OS_MACOSX)
   {
     "enable-simplified-fullscreen",
     IDS_FLAGS_ENABLE_SIMPLIFIED_FULLSCREEN_NAME,
     IDS_FLAGS_ENABLE_SIMPLIFIED_FULLSCREEN_DESCRIPTION,
     kOsMac,
-    SINGLE_VALUE_TYPE(switches::kEnableSimplifiedFullscreen)
+    SINGLE_VALUE_TYPE(switches::kEnableSimplifiedFullscreen,
+                      UMA_HISTOGRAM_ID_kEnableSimplifiedFullscreen)
   },
 #endif
 #if defined(USE_AURA)
   {
     "tab-capture-upscale-quality",
     IDS_FLAGS_TAB_CAPTURE_UPSCALE_QUALITY_NAME,
     IDS_FLAGS_TAB_CAPTURE_UPSCALE_QUALITY_DESCRIPTION,
     kOsAll,
     MULTI_VALUE_TYPE(kTabCaptureUpscaleQualityChoices)
   },
   {
     "tab-capture-downscale-quality",
     IDS_FLAGS_TAB_CAPTURE_DOWNSCALE_QUALITY_NAME,
     IDS_FLAGS_TAB_CAPTURE_DOWNSCALE_QUALITY_DESCRIPTION,
     kOsAll,
     MULTI_VALUE_TYPE(kTabCaptureDownscaleQualityChoices)
   },
 #endif
   {
     "enable-spelling-feedback-field-trial",
     IDS_FLAGS_ENABLE_SPELLING_FEEDBACK_FIELD_TRIAL_NAME,
     IDS_FLAGS_ENABLE_SPELLING_FEEDBACK_FIELD_TRIAL_DESCRIPTION,
     kOsAll,
-    SINGLE_VALUE_TYPE(switches::kEnableSpellingFeedbackFieldTrial)
+    SINGLE_VALUE_TYPE(switches::kEnableSpellingFeedbackFieldTrial,
+                      UMA_HISTOGRAM_ID_kEnableSpellingFeedbackFieldTrial)
   },
   {
     "enable-webgl-draft-extensions",
     IDS_FLAGS_ENABLE_WEBGL_DRAFT_EXTENSIONS_NAME,
     IDS_FLAGS_ENABLE_WEBGL_DRAFT_EXTENSIONS_DESCRIPTION,
     kOsAll,
-    SINGLE_VALUE_TYPE(switches::kEnableWebGLDraftExtensions)
+    SINGLE_VALUE_TYPE(switches::kEnableWebGLDraftExtensions,
+                      UMA_HISTOGRAM_ID_kEnableWebGLDraftExtensions)
   },
   {
     "enable-web-midi",
     IDS_FLAGS_ENABLE_WEB_MIDI_NAME,
     IDS_FLAGS_ENABLE_WEB_MIDI_DESCRIPTION,
     kOsMac | kOsWin | kOsLinux | kOsCrOS | kOsAndroid,
-    SINGLE_VALUE_TYPE(switches::kEnableWebMIDI)
+    SINGLE_VALUE_TYPE(switches::kEnableWebMIDI,
+                      UMA_HISTOGRAM_ID_kEnableWebMIDI)
   },
   {
     "enable-new-profile-management",
     IDS_FLAGS_ENABLE_NEW_PROFILE_MANAGEMENT_NAME,
     IDS_FLAGS_ENABLE_NEW_PROFILE_MANAGEMENT_DESCRIPTION,
     kOsAndroid | kOsMac | kOsWin | kOsLinux | kOsCrOS,
     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableNewProfileManagement,
-                              switches::kDisableNewProfileManagement)
+                              UMA_HISTOGRAM_ID_kEnableNewProfileManagement,
+                              switches::kDisableNewProfileManagement,
+                              UMA_HISTOGRAM_ID_kDisableNewProfileManagement)
   },
   {
     "enable-account-consistency",
     IDS_FLAGS_ENABLE_ACCOUNT_CONSISTENCY_NAME,
     IDS_FLAGS_ENABLE_ACCOUNT_CONSISTENCY_DESCRIPTION,
     kOsAndroid | kOsMac | kOsWin | kOsLinux | kOsCrOS,
     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableAccountConsistency,
-                              switches::kDisableAccountConsistency)
+                              UMA_HISTOGRAM_ID_kEnableAccountConsistency,
+                              switches::kDisableAccountConsistency,
+                              UMA_HISTOGRAM_ID_kDisableAccountConsistency)
   },
   {
     "enable-fast-user-switching",
     IDS_FLAGS_ENABLE_FAST_USER_SWITCHING_NAME,
     IDS_FLAGS_ENABLE_FAST_USER_SWITCHING_DESCRIPTION,
     kOsMac | kOsWin | kOsLinux,
-    SINGLE_VALUE_TYPE(switches::kFastUserSwitching)
+    SINGLE_VALUE_TYPE(switches::kFastUserSwitching,
+                      UMA_HISTOGRAM_ID_kFastUserSwitching)
   },
   {
     "enable-new-avatar-menu",
     IDS_FLAGS_ENABLE_NEW_AVATAR_MENU_NAME,
     IDS_FLAGS_ENABLE_NEW_AVATAR_MENU_DESCRIPTION,
     kOsMac | kOsWin | kOsLinux,
-    SINGLE_VALUE_TYPE(switches::kNewAvatarMenu)
+    SINGLE_VALUE_TYPE(switches::kNewAvatarMenu,
+                      UMA_HISTOGRAM_ID_kNewAvatarMenu)
   },
   {
     "enable-web-based-signin",
     IDS_FLAGS_ENABLE_WEB_BASED_SIGNIN_NAME,
     IDS_FLAGS_ENABLE_WEB_BASED_SIGNIN_DESCRIPTION,
     kOsMac | kOsWin | kOsLinux,
-    SINGLE_VALUE_TYPE(switches::kEnableWebBasedSignin)
+    SINGLE_VALUE_TYPE(switches::kEnableWebBasedSignin,
+                      UMA_HISTOGRAM_ID_kEnableWebBasedSignin)
   },
   {
     "enable-google-profile-info",
     IDS_FLAGS_ENABLE_GOOGLE_PROFILE_INFO_NAME,
     IDS_FLAGS_ENABLE_GOOGLE_PROFILE_INFO_DESCRIPTION,
     kOsMac | kOsWin | kOsLinux,
-    SINGLE_VALUE_TYPE(switches::kGoogleProfileInfo)
+    SINGLE_VALUE_TYPE(switches::kGoogleProfileInfo,
+                      UMA_HISTOGRAM_ID_kGoogleProfileInfo)
   },
   {
     "reset-app-list-install-state",
     IDS_FLAGS_RESET_APP_LIST_INSTALL_STATE_NAME,
     IDS_FLAGS_RESET_APP_LIST_INSTALL_STATE_DESCRIPTION,
     kOsMac | kOsWin | kOsLinux,
-    SINGLE_VALUE_TYPE(switches::kResetAppListInstallState)
+    SINGLE_VALUE_TYPE(switches::kResetAppListInstallState,
+                      UMA_HISTOGRAM_ID_kResetAppListInstallState)
   },
 #if defined(ENABLE_APP_LIST)
 #if defined(OS_LINUX)
-  {
-    // This is compiled out on non-Linux platforms because otherwise it would be
+  { // This is compiled out on non-Linux platforms because otherwise it would
+    // be
     // visible on Win/Mac/CrOS but not on Linux GTK, which would be confusing.
     // TODO(mgiuca): Remove the #if when Aura is the default on Linux.
     "enable-app-list",
     IDS_FLAGS_ENABLE_APP_LIST_NAME,
     IDS_FLAGS_ENABLE_APP_LIST_DESCRIPTION,
     kOsLinux,
-    SINGLE_VALUE_TYPE(switches::kEnableAppList)
+    SINGLE_VALUE_TYPE(switches::kEnableAppList,
+                      UMA_HISTOGRAM_ID_kEnableAppList)
   },
 #endif
   {
     "disable-app-list-app-info",
     IDS_FLAGS_DISABLE_APP_INFO_IN_APP_LIST,
     IDS_FLAGS_DISABLE_APP_INFO_IN_APP_LIST_DESCRIPTION,
     kOsLinux | kOsWin | kOsCrOS,
-    SINGLE_VALUE_TYPE(app_list::switches::kDisableAppInfo)
+    SINGLE_VALUE_TYPE(app_list::switches::kDisableAppInfo,
+                      UMA_HISTOGRAM_ID_kDisableAppInfo)
   },
   {
     "disable-app-list-voice-search",
     IDS_FLAGS_DISABLE_APP_LIST_VOICE_SEARCH,
     IDS_FLAGS_DISABLE_APP_LIST_VOICE_SEARCH_DESCRIPTION,
     kOsCrOS,
-    SINGLE_VALUE_TYPE(app_list::switches::kDisableVoiceSearch)
+    SINGLE_VALUE_TYPE(app_list::switches::kDisableVoiceSearch,
+                      UMA_HISTOGRAM_ID_kDisableVoiceSearch)
   },
 #endif
 #if defined(OS_ANDROID)
   {
     "enable-accessibility-tab-switcher",
     IDS_FLAGS_ENABLE_ACCESSIBILITY_TAB_SWITCHER_NAME,
     IDS_FLAGS_ENABLE_ACCESSIBILITY_TAB_SWITCHER_DESCRIPTION,
     kOsAndroid,
-    SINGLE_VALUE_TYPE(switches::kEnableAccessibilityTabSwitcher)
-  },
-  {
-    // TODO(dmazzoni): remove this flag when native android accessibility
-    // ships in the stable channel. http://crbug.com/356775
-    "enable-accessibility-script-injection",
-    IDS_FLAGS_ENABLE_ACCESSIBILITY_SCRIPT_INJECTION_NAME,
-    IDS_FLAGS_ENABLE_ACCESSIBILITY_SCRIPT_INJECTION_DESCRIPTION,
-    kOsAndroid,
-    // Java-only switch: ContentSwitches.ENABLE_ACCESSIBILITY_SCRIPT_INJECTION.
-    SINGLE_VALUE_TYPE("enable-accessibility-script-injection")
+    SINGLE_VALUE_TYPE(switches::kEnableAccessibilityTabSwitcher,
+                      UMA_HISTOGRAM_ID_kEnableAccessibilityTabSwitcher)
   },
 #endif
   {
     "enable-one-copy",
     IDS_FLAGS_ONE_COPY_NAME,
     IDS_FLAGS_ONE_COPY_DESCRIPTION,
     kOsAll,
-    SINGLE_VALUE_TYPE(switches::kEnableOneCopy)
+    SINGLE_VALUE_TYPE(switches::kEnableOneCopy,
+                      UMA_HISTOGRAM_ID_kEnableOneCopy)
   },
   {
     "enable-zero-copy",
     IDS_FLAGS_ZERO_COPY_NAME,
     IDS_FLAGS_ZERO_COPY_DESCRIPTION,
     kOsAll,
     MULTI_VALUE_TYPE(kZeroCopyChoices)
   },
 #if defined(OS_CHROMEOS)
   {
     "enable-first-run-ui-transitions",
     IDS_FLAGS_ENABLE_FIRST_RUN_UI_TRANSITIONS_NAME,
     IDS_FLAGS_ENABLE_FIRST_RUN_UI_TRANSITIONS_DESCRIPTION,
     kOsCrOS,
-    SINGLE_VALUE_TYPE(chromeos::switches::kEnableFirstRunUITransitions)
+    SINGLE_VALUE_TYPE(chromeos::switches::kEnableFirstRunUITransitions,
+                      UMA_HISTOGRAM_ID_kEnableFirstRunUITransitions)
   },
 #endif
   {
     "disable-compositor-touch-hit-testing",
     IDS_FLAGS_DISABLE_COMPOSITOR_TOUCH_HIT_TESTING_NAME,
     IDS_FLAGS_DISABLE_COMPOSITOR_TOUCH_HIT_TESTING_DESCRIPTION,
     kOsAll,
-    SINGLE_VALUE_TYPE(cc::switches::kDisableCompositorTouchHitTesting),
+    SINGLE_VALUE_TYPE(cc::switches::kDisableCompositorTouchHitTesting,
+                      UMA_HISTOGRAM_ID_kDisableCompositorTouchHitTesting)
   },
   {
     "enable-streamlined-hosted-apps",
     IDS_FLAGS_ENABLE_STREAMLINED_HOSTED_APPS_NAME,
     IDS_FLAGS_ENABLE_STREAMLINED_HOSTED_APPS_DESCRIPTION,
     kOsWin | kOsCrOS | kOsLinux,
-    SINGLE_VALUE_TYPE(switches::kEnableStreamlinedHostedApps)
+    SINGLE_VALUE_TYPE(switches::kEnableStreamlinedHostedApps,
+                      UMA_HISTOGRAM_ID_kEnableStreamlinedHostedApps)
   },
   {
     "enable-prominent-url-app-flow",
     IDS_FLAGS_ENABLE_PROMINENT_URL_APP_FLOW_NAME,
     IDS_FLAGS_ENABLE_PROMINENT_URL_APP_FLOW_DESCRIPTION,
     kOsWin | kOsCrOS | kOsLinux,
-    SINGLE_VALUE_TYPE(switches::kEnableProminentURLAppFlow)
+    SINGLE_VALUE_TYPE(switches::kEnableProminentURLAppFlow,
+                      UMA_HISTOGRAM_ID_kEnableProminentURLAppFlow)
   },
   {
     "enable-ephemeral-apps",
     IDS_FLAGS_ENABLE_EPHEMERAL_APPS_NAME,
     IDS_FLAGS_ENABLE_EPHEMERAL_APPS_DESCRIPTION,
     kOsAll,
-    SINGLE_VALUE_TYPE(switches::kEnableEphemeralApps)
+    SINGLE_VALUE_TYPE(switches::kEnableEphemeralApps,
+                      UMA_HISTOGRAM_ID_kEnableEphemeralApps)
   },
   {
     "enable-linkable-ephemeral-apps",
     IDS_FLAGS_ENABLE_LINKABLE_EPHEMERAL_APPS_NAME,
     IDS_FLAGS_ENABLE_LINKABLE_EPHEMERAL_APPS_DESCRIPTION,
     kOsAll,
-    SINGLE_VALUE_TYPE(switches::kEnableLinkableEphemeralApps)
+    SINGLE_VALUE_TYPE(switches::kEnableLinkableEphemeralApps,
+                      UMA_HISTOGRAM_ID_kEnableLinkableEphemeralApps)
   },
   {
     "enable-service-worker",
     IDS_FLAGS_ENABLE_SERVICE_WORKER_NAME,
     IDS_FLAGS_ENABLE_SERVICE_WORKER_DESCRIPTION,
     kOsAll,
-    SINGLE_VALUE_TYPE(switches::kEnableServiceWorker)
+    SINGLE_VALUE_TYPE(switches::kEnableServiceWorker,
+                      UMA_HISTOGRAM_ID_kEnableServiceWorker)
   },
   {
     "enable-service-worker-sync",
     IDS_FLAGS_ENABLE_SERVICE_WORKER_SYNC_NAME,
     IDS_FLAGS_ENABLE_SERVICE_WORKER_SYNC_DESCRIPTION,
     kOsAll,
-    SINGLE_VALUE_TYPE(switches::kEnableServiceWorkerSync)
+    SINGLE_VALUE_TYPE(switches::kEnableServiceWorkerSync,
+                      UMA_HISTOGRAM_ID_kEnableServiceWorkerSync)
   },
 #if defined(OS_ANDROID)
   {
     "disable-click-delay",
     IDS_FLAGS_DISABLE_CLICK_DELAY_NAME,
     IDS_FLAGS_DISABLE_CLICK_DELAY_DESCRIPTION,
     kOsAndroid,
     // Java-only switch: CommandLine.DISABLE_CLICK_DELAY
-    SINGLE_VALUE_TYPE("disable-click-delay")
+    SINGLE_VALUE_TYPE(switches::kDisableClickDelay,
+                      UMA_HISTOGRAM_ID_kDisableClickDelay)
   },
 #endif
 #if defined(OS_MACOSX)
   {
     "enable-translate-new-ux",
     IDS_FLAGS_ENABLE_TRANSLATE_NEW_UX_NAME,
     IDS_FLAGS_ENABLE_TRANSLATE_NEW_UX_DESCRIPTION,
     kOsMac,
-    SINGLE_VALUE_TYPE(switches::kEnableTranslateNewUX)
+    SINGLE_VALUE_TYPE(switches::kEnableTranslateNewUX,
+                      UMA_HISTOGRAM_ID_kEnableTranslateNewUX)
   },
 #endif
 #if defined(TOOLKIT_VIEWS)
   {
     "disable-views-rect-based-targeting",  // FLAGS:RECORD_UMA
     IDS_FLAGS_DISABLE_VIEWS_RECT_BASED_TARGETING_NAME,
     IDS_FLAGS_DISABLE_VIEWS_RECT_BASED_TARGETING_DESCRIPTION,
     kOsCrOS | kOsWin,
-    SINGLE_VALUE_TYPE(views::switches::kDisableViewsRectBasedTargeting)
+    SINGLE_VALUE_TYPE(views::switches::kDisableViewsRectBasedTargeting,
+                      UMA_HISTOGRAM_ID_kDisableViewsRectBasedTargeting)
   },
 #endif
   {
     "enable-apps-show-on-first-paint",
     IDS_FLAGS_ENABLE_APPS_SHOW_ON_FIRST_PAINT_NAME,
     IDS_FLAGS_ENABLE_APPS_SHOW_ON_FIRST_PAINT_DESCRIPTION,
     kOsDesktop,
-    SINGLE_VALUE_TYPE(switches::kEnableAppsShowOnFirstPaint)
+    SINGLE_VALUE_TYPE(switches::kEnableAppsShowOnFirstPaint,
+                      UMA_HISTOGRAM_ID_kEnableAppsShowOnFirstPaint)
   },
   {
     "enhanced-bookmarks-experiment",
     IDS_FLAGS_ENABLE_ENHANCED_BOOKMARKS_NAME,
     IDS_FLAGS_ENABLE_ENHANCED_BOOKMARKS_DESCRIPTION,
     kOsDesktop,
     ENABLE_DISABLE_VALUE_TYPE_AND_VALUE(
         switches::kEnhancedBookmarksExperiment, "1",
-        switches::kEnhancedBookmarksExperiment, "0")
+        UMA_HISTOGRAM_ID_kEnhancedBookmarksExperiment,
+        switches::kEnhancedBookmarksExperiment, "0",
+        UMA_HISTOGRAM_ID_kEnhancedBookmarksExperiment)
   },
   {
     "manual-enhanced-bookmarks",
     IDS_FLAGS_ENABLE_ENHANCED_BOOKMARKS_NAME,
     IDS_FLAGS_ENABLE_ENHANCED_BOOKMARKS_DESCRIPTION,
     kOsDesktop,
-    SINGLE_VALUE_TYPE(switches::kManualEnhancedBookmarks)
+    SINGLE_VALUE_TYPE(switches::kManualEnhancedBookmarks,
+                      UMA_HISTOGRAM_ID_kManualEnhancedBookmarks)
   },
   {
     "manual-enhanced-bookmarks-optout",
     IDS_FLAGS_ENABLE_ENHANCED_BOOKMARKS_NAME,
     IDS_FLAGS_ENABLE_ENHANCED_BOOKMARKS_DESCRIPTION,
     kOsDesktop,
-    SINGLE_VALUE_TYPE(switches::kManualEnhancedBookmarksOptout)
+    SINGLE_VALUE_TYPE(switches::kManualEnhancedBookmarksOptout,
+                      UMA_HISTOGRAM_ID_kManualEnhancedBookmarksOptout)
   },
 #if defined(OS_ANDROID)
   {
     "enable-zero-suggest-experiment",
     IDS_FLAGS_ZERO_SUGGEST_EXPERIMENT_NAME,
     IDS_FLAGS_ZERO_SUGGEST_EXPERIMENT_DESCRIPTION,
     kOsAndroid,
     MULTI_VALUE_TYPE(kZeroSuggestExperimentsChoices)
   },
 #endif
@@ skipping 16 matching lines @@
     IDS_FLAGS_SEARCH_BUTTON_IN_OMNIBOX_NAME,
     IDS_FLAGS_SEARCH_BUTTON_IN_OMNIBOX_DESCRIPTION,
     kOsCrOS | kOsMac | kOsWin | kOsLinux,
     MULTI_VALUE_TYPE(kSearchButtonInOmniboxChoices)
   },
   {
     "disable-ignore-autocomplete-off",
     IDS_FLAGS_DISABLE_IGNORE_AUTOCOMPLETE_OFF_NAME,
     IDS_FLAGS_DISABLE_IGNORE_AUTOCOMPLETE_OFF_DESCRIPTION,
     kOsAll,
-    SINGLE_VALUE_TYPE(autofill::switches::kDisableIgnoreAutocompleteOff)
+    SINGLE_VALUE_TYPE(autofill::switches::kDisableIgnoreAutocompleteOff,
+                      UMA_HISTOGRAM_ID_kDisableIgnoreAutocompleteOff)
   },
   {
     "enable-permissions-bubbles",
     IDS_FLAGS_ENABLE_PERMISSIONS_BUBBLES_NAME,
     IDS_FLAGS_ENABLE_PERMISSIONS_BUBBLES_DESCRIPTION,
     kOsAll,
     ENABLE_DISABLE_VALUE_TYPE(switches::kEnablePermissionsBubbles,
-                              switches::kDisablePermissionsBubbles)
+                              UMA_HISTOGRAM_ID_kEnablePermissionsBubbles,
+                              switches::kDisablePermissionsBubbles,
+                              UMA_HISTOGRAM_ID_kDisablePermissionsBubbles)
   },
   {
     "enable-session-crashed-bubble",
     IDS_FLAGS_ENABLE_SESSION_CRASHED_BUBBLE_NAME,
     IDS_FLAGS_ENABLE_SESSION_CRASHED_BUBBLE_DESCRIPTION,
     kOsWin | kOsLinux,
     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableSessionCrashedBubble,
-                              switches::kDisableSessionCrashedBubble)
+                              UMA_HISTOGRAM_ID_kEnableSessionCrashedBubble,
+                              switches::kDisableSessionCrashedBubble,
+                              UMA_HISTOGRAM_ID_kDisableSessionCrashedBubble)
   },
   {
     "out-of-process-pdf",
     IDS_FLAGS_OUT_OF_PROCESS_PDF_NAME,
     IDS_FLAGS_OUT_OF_PROCESS_PDF_DESCRIPTION,
     kOsDesktop,
-    SINGLE_VALUE_TYPE(switches::kOutOfProcessPdf)
+    SINGLE_VALUE_TYPE(switches::kOutOfProcessPdf,
+                      UMA_HISTOGRAM_ID_kOutOfProcessPdf)
   },
 #if defined(OS_ANDROID)
   {
     "enable-fast-text-autosizing",
     IDS_FLAGS_ENABLE_FAST_TEXT_AUTOSIZING_NAME,
     IDS_FLAGS_ENABLE_FAST_TEXT_AUTOSIZING_DESCRIPTION,
     kOsAndroid,
     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableFastTextAutosizing,
-                              switches::kDisableFastTextAutosizing)
+                              UMA_HISTOGRAM_ID_kEnableFastTextAutosizing,
+                              switches::kDisableFastTextAutosizing,
+                              UMA_HISTOGRAM_ID_kDisableFastTextAutosizing)
   },
   {
     "disable-cast",
     IDS_FLAGS_DISABLE_CAST_NAME,
     IDS_FLAGS_DISABLE_CAST_DESCRIPTION,
     kOsAndroid,
-    SINGLE_VALUE_TYPE(switches::kDisableCast)
+    SINGLE_VALUE_TYPE(switches::kDisableCast, UMA_HISTOGRAM_ID_kDisableCast)
   },
   {
     "prefetch-search-results",
     IDS_FLAGS_PREFETCH_SEARCH_RESULTS_NAME,
     IDS_FLAGS_PREFETCH_SEARCH_RESULTS_DESCRIPTION,
     kOsAndroid,
-    SINGLE_VALUE_TYPE(switches::kPrefetchSearchResults)
+    SINGLE_VALUE_TYPE(switches::kPrefetchSearchResults,
+                      UMA_HISTOGRAM_ID_kPrefetchSearchResults)
   },
 #endif
 #if defined(ENABLE_APP_LIST)
   {
     "enable-experimental-app-list",
     IDS_FLAGS_ENABLE_EXPERIMENTAL_APP_LIST_NAME,
     IDS_FLAGS_ENABLE_EXPERIMENTAL_APP_LIST_DESCRIPTION,
     kOsWin | kOsLinux | kOsCrOS,
-    SINGLE_VALUE_TYPE(app_list::switches::kEnableExperimentalAppList)
+    SINGLE_VALUE_TYPE(app_list::switches::kEnableExperimentalAppList,
+                      UMA_HISTOGRAM_ID_kEnableExperimentalAppList)
   },
   {
     "enable-centered-app-list",
     IDS_FLAGS_ENABLE_CENTERED_APP_LIST_NAME,
     IDS_FLAGS_ENABLE_CENTERED_APP_LIST_DESCRIPTION,
     kOsWin | kOsLinux | kOsCrOS,
-    SINGLE_VALUE_TYPE(app_list::switches::kEnableCenteredAppList)
+    SINGLE_VALUE_TYPE(app_list::switches::kEnableCenteredAppList,
+                      UMA_HISTOGRAM_ID_kEnableCenteredAppList)
   },
 #endif
   {
     "touch-scrolling-mode",
     IDS_FLAGS_TOUCH_SCROLLING_MODE_NAME,
     IDS_FLAGS_TOUCH_SCROLLING_MODE_DESCRIPTION,
     kOsWin | kOsLinux | kOsCrOS | kOsAndroid,
     MULTI_VALUE_TYPE(kTouchScrollingModeChoices)
   },
   {
     "bleeding-edge-renderer-mode",
     IDS_FLAGS_BLEEDING_RENDERER_NAME,
     IDS_FLAGS_BLEEDING_RENDERER_DESCRIPTION,
     kOsAndroid,
-    SINGLE_VALUE_TYPE(switches::kEnableBleedingEdgeRenderingFastPaths)
+    SINGLE_VALUE_TYPE(switches::kEnableBleedingEdgeRenderingFastPaths,
+                      UMA_HISTOGRAM_ID_kEnableBleedingEdgeRenderingFastPaths)
   },
   {
     "enable-settings-window",
     IDS_FLAGS_ENABLE_SETTINGS_WINDOW_NAME,
     IDS_FLAGS_ENABLE_SETTINGS_WINDOW_DESCRIPTION,
     kOsDesktop,
     MULTI_VALUE_TYPE(kEnableSettingsWindowChoices)
   },
 #if defined(OS_ANDROID)
   {
     "enable-instant-search-clicks",
     IDS_FLAGS_ENABLE_INSTANT_SEARCH_CLICKS_NAME,
     IDS_FLAGS_ENABLE_INSTANT_SEARCH_CLICKS_DESCRIPTION,
     kOsAndroid,
-    SINGLE_VALUE_TYPE(switches::kEnableInstantSearchClicks)
+    SINGLE_VALUE_TYPE(switches::kEnableInstantSearchClicks,
+                      UMA_HISTOGRAM_ID_kEnableInstantSearchClicks)
   },
 #endif
   {
     "enable-save-password-bubble",
     IDS_FLAGS_ENABLE_SAVE_PASSWORD_BUBBLE_NAME,
     IDS_FLAGS_ENABLE_SAVE_PASSWORD_BUBBLE_DESCRIPTION,
     kOsWin | kOsLinux | kOsCrOS,
     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableSavePasswordBubble,
-                              switches::kDisableSavePasswordBubble)
+                              UMA_HISTOGRAM_ID_kEnableSavePasswordBubble,
+                              switches::kDisableSavePasswordBubble,
+                              UMA_HISTOGRAM_ID_kDisableSavePasswordBubble)
   },
 #if defined(GOOGLE_CHROME_BUILD)
   {
     "enable-easy-unlock",
     IDS_FLAGS_ENABLE_EASY_UNLOCK_NAME,
     IDS_FLAGS_ENABLE_EASY_UNLOCK_DESCRIPTION,
     kOsCrOS,
-    SINGLE_VALUE_TYPE(switches::kEnableEasyUnlock)
+    SINGLE_VALUE_TYPE(switches::kEnableEasyUnlock,
+                      UMA_HISTOGRAM_ID_kEnableEasyUnlock)
   },
 #endif
   {
     "disable-embedded-shared-worker",
     IDS_FLAGS_DISABLE_EMBEDDED_SHARED_WORKER_NAME,
     IDS_FLAGS_DISABLE_EMBEDDED_SHARED_WORKER_DESCRIPTION,
     kOsDesktop,
-    SINGLE_VALUE_TYPE(switches::kDisableEmbeddedSharedWorker)
+    SINGLE_VALUE_TYPE(switches::kDisableEmbeddedSharedWorker,
+                      UMA_HISTOGRAM_ID_kDisableEmbeddedSharedWorker)
   },
 #if defined(OS_CHROMEOS)
   {
     "enable-filemanager-mtp",
     IDS_FLAGS_ENABLE_FILE_MANAGER_MTP_NAME,
     IDS_FLAGS_ENABLE_FILE_MANAGER_MTP_DESCRIPTION,
     kOsCrOS,
     MULTI_VALUE_TYPE(kEnableFileManagerMTPChoices)
   },
 #endif
   // TODO(tyoshino): Remove this temporary flag and command line switch. See
   // crbug.com/366483 for the target milestone.
   {
     "allow-insecure-websocket-from-https-origin",
     IDS_FLAGS_ALLOW_INSECURE_WEBSOCKET_FROM_HTTPS_ORIGIN_NAME,
     IDS_FLAGS_ALLOW_INSECURE_WEBSOCKET_FROM_HTTPS_ORIGIN_DESCRIPTION,
     kOsAll,
-    SINGLE_VALUE_TYPE(switches::kAllowInsecureWebSocketFromHttpsOrigin)
+    SINGLE_VALUE_TYPE(
+        switches::kAllowInsecureWebSocketFromHttpsOrigin,
+        UMA_HISTOGRAM_ID_kAllowInsecureWebSocketFromHttpsOrigin)
   },
 #if defined(OS_MACOSX)
   {
     "apps-keep-chrome-alive",
     IDS_FLAGS_APPS_KEEP_CHROME_ALIVE_NAME,
     IDS_FLAGS_APPS_KEEP_CHROME_ALIVE_DESCRIPTION,
     kOsMac,
-    SINGLE_VALUE_TYPE(switches::kAppsKeepChromeAlive)
+    SINGLE_VALUE_TYPE(switches::kAppsKeepChromeAlive,
+                      UMA_HISTOGRAM_ID_kAppsKeepChromeAlive)
   },
 #endif
   {
     "enable-apps-file-associations",
     IDS_FLAGS_ENABLE_APPS_FILE_ASSOCIATIONS_NAME,
     IDS_FLAGS_ENABLE_APPS_FILE_ASSOCIATIONS_DESCRIPTION,
     kOsMac,
-    SINGLE_VALUE_TYPE(switches::kEnableAppsFileAssociations)
+    SINGLE_VALUE_TYPE(switches::kEnableAppsFileAssociations,
+                      UMA_HISTOGRAM_ID_kEnableAppsFileAssociations)
   },
 #if defined(OS_ANDROID)
   {
     "enable-embeddedsearch-api",
     IDS_FLAGS_ENABLE_EMBEDDEDSEARCH_API_NAME,
     IDS_FLAGS_ENABLE_EMBEDDEDSEARCH_API_DESCRIPTION,
     kOsAndroid,
-    SINGLE_VALUE_TYPE(switches::kEnableEmbeddedSearchAPI)
+    SINGLE_VALUE_TYPE(switches::kEnableEmbeddedSearchAPI,
+                      UMA_HISTOGRAM_ID_kEnableEmbeddedSearchAPI)
   },
   {
     "enable-app-install-alerts",
     IDS_FLAGS_ENABLE_APP_INSTALL_ALERTS_NAME,
     IDS_FLAGS_ENABLE_APP_INSTALL_ALERTS_DESCRIPTION,
     kOsAndroid,
-    SINGLE_VALUE_TYPE(switches::kEnableAppInstallAlerts)
+    SINGLE_VALUE_TYPE(switches::kEnableAppInstallAlerts,
+                      UMA_HISTOGRAM_ID_kEnableAppInstallAlerts)
   },
 #endif
   {
     "distance-field-text",
     IDS_FLAGS_DISTANCE_FIELD_TEXT_NAME,
     IDS_FLAGS_DISTANCE_FIELD_TEXT_DESCRIPTION,
     kOsAll,
     MULTI_VALUE_TYPE(kDistanceFieldTextChoices)
   },
   {
     "extension-content-verification",
     IDS_FLAGS_EXTENSION_CONTENT_VERIFICATION_NAME,
     IDS_FLAGS_EXTENSION_CONTENT_VERIFICATION_DESCRIPTION,
     kOsDesktop,
     MULTI_VALUE_TYPE(kExtensionContentVerificationChoices)
   },
 #if defined(USE_AURA)
   {
     "text-input-focus-manager",
     IDS_FLAGS_TEXT_INPUT_FOCUS_MANAGER_NAME,
     IDS_FLAGS_TEXT_INPUT_FOCUS_MANAGER_DESCRIPTION,
     kOsCrOS | kOsLinux | kOsWin,
     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableTextInputFocusManager,
-                              switches::kDisableTextInputFocusManager)
+                              UMA_HISTOGRAM_ID_kEnableTextInputFocusManager,
+                              switches::kDisableTextInputFocusManager,
+                              UMA_HISTOGRAM_ID_kDisableTextInputFocusManager)
   },
 #endif
   {
     "extension-active-script-permission",
     IDS_FLAGS_USER_CONSENT_FOR_EXTENSION_SCRIPTS_NAME,
     IDS_FLAGS_USER_CONSENT_FOR_EXTENSION_SCRIPTS_DESCRIPTION,
     kOsAll,
-    SINGLE_VALUE_TYPE(extensions::switches::kEnableScriptsRequireAction)
+    SINGLE_VALUE_TYPE(extensions::switches::kEnableScriptsRequireAction,
+                      UMA_HISTOGRAM_ID_kEnableScriptsRequireAction)
   },
   {
     "enable-harfbuzz-rendertext",
     IDS_FLAGS_ENABLE_HARFBUZZ_RENDERTEXT_NAME,
     IDS_FLAGS_ENABLE_HARFBUZZ_RENDERTEXT_DESCRIPTION,
     kOsDesktop,
-    SINGLE_VALUE_TYPE(switches::kEnableHarfBuzzRenderText)
+    SINGLE_VALUE_TYPE(switches::kEnableHarfBuzzRenderText,
+                      UMA_HISTOGRAM_ID_kEnableHarfBuzzRenderText)
   },
 #if defined(OS_ANDROID)
   {
     "enable-answers-in-suggest",
     IDS_FLAGS_ENABLE_ANSWERS_IN_SUGGEST_NAME,
     IDS_FLAGS_ENABLE_ANSWERS_IN_SUGGEST_DESCRIPTION,
     kOsAndroid,
-    SINGLE_VALUE_TYPE(switches::kEnableAnswersInSuggest)
+    SINGLE_VALUE_TYPE(switches::kEnableAnswersInSuggest,
+                      UMA_HISTOGRAM_ID_kEnableAnswersInSuggest)
   },
 #endif
   {
     "ssl-interstitial-version",
     IDS_FLAGS_SSL_INTERSTITIAL_TRIAL_NAME,
     IDS_FLAGS_SSL_INTERSTITIAL_TRIAL_DESCRIPTION,
     kOsAll,
     MULTI_VALUE_TYPE(kSSLInterstitialVersions)
   },
   {
     "malware-interstitial-version",
     IDS_FLAGS_MALWARE_INTERSTITIAL_TRIAL_NAME,
     IDS_FLAGS_MALWARE_INTERSTITIAL_TRIAL_DESCRIPTION,
     kOsAll,
     MULTI_VALUE_TYPE(kMalwareInterstitialVersions)
   },
 #if defined(OS_ANDROID)
   {
     "enable-data-reduction-proxy-dev",
     IDS_FLAGS_ENABLE_DATA_REDUCTION_PROXY_DEV_NAME,
     IDS_FLAGS_ENABLE_DATA_REDUCTION_PROXY_DEV_DESCRIPTION,
     kOsAndroid,
     ENABLE_DISABLE_VALUE_TYPE(
         data_reduction_proxy::switches::kEnableDataReductionProxyDev,
-        data_reduction_proxy::switches::kDisableDataReductionProxyDev)
+        UMA_HISTOGRAM_ID_kEnableDataReductionProxyDev,
+        data_reduction_proxy::switches::kDisableDataReductionProxyDev,
+        UMA_HISTOGRAM_ID_kDisableDataReductionProxyDev)
   },
 #endif
 };
 
 const Experiment* experiments = kExperiments;
 size_t num_experiments = arraysize(kExperiments);
 
 // Stores and encapsulates the little state that about:flags has.
 class FlagsState {
  public:
   FlagsState() : needs_restart_(false) {}
   void ConvertFlagsToSwitches(FlagsStorage* flags_storage,
                               CommandLine* command_line,
                               SentinelsMode sentinels);
+  const SwitchesHistogramIDs& GetSwitchesHistogramIds();
   bool IsRestartNeededToCommitChanges();
   void SetExperimentEnabled(
       FlagsStorage* flags_storage,
       const std::string& internal_name,
       bool enable);
   void RemoveFlagsSwitches(
       std::map<std::string, CommandLine::StringType>* switch_list);
   void ResetAllFlags(FlagsStorage* flags_storage);
   void reset();
 
   // Returns the singleton instance of this class
   static FlagsState* GetInstance() {
     return Singleton<FlagsState>::get();
   }
 
  private:
   bool needs_restart_;
   std::map<std::string, std::string> flags_switches_;
+  // Lazy initialized by GetSwitchesHistogramIds().
+  SwitchesHistogramIDs switches_histogram_id_;
 
   DISALLOW_COPY_AND_ASSIGN(FlagsState);
 };
 
 // Adds the internal names for the specified experiment to |names|.
 void AddInternalName(const Experiment& e, std::set<std::string>* names) {
   if (e.type == Experiment::SINGLE_VALUE) {
     names->insert(e.internal_name);
   } else {
     DCHECK(e.type == Experiment::MULTI_VALUE ||
@@ skipping 160 matching lines @@
 }
 
 void ConvertFlagsToSwitches(FlagsStorage* flags_storage,
                             CommandLine* command_line,
                             SentinelsMode sentinels) {
   FlagsState::GetInstance()->ConvertFlagsToSwitches(flags_storage,
                                                     command_line,
                                                     sentinels);
 }
 
+const SwitchesHistogramIDs& GetSwitchesHistogramIds() {
+  return FlagsState::GetInstance()->GetSwitchesHistogramIds();
+}
+
 bool AreSwitchesIdenticalToCurrentCommandLine(
-    const CommandLine& new_cmdline, const CommandLine& active_cmdline) {
+    const CommandLine& new_cmdline,
+    const CommandLine& active_cmdline,
+    std::set<CommandLine::StringType>* out_difference) {
   std::set<CommandLine::StringType> new_flags =
       ExtractFlagsFromCommandLine(new_cmdline);
   std::set<CommandLine::StringType> active_flags =
       ExtractFlagsFromCommandLine(active_cmdline);
 
+  bool result = false;
   // Needed because std::equal doesn't check if the 2nd set is empty.
-  if (new_flags.size() != active_flags.size())
-    return false;
+  if (new_flags.size() == active_flags.size()) {
+    result =
+        std::equal(new_flags.begin(), new_flags.end(), active_flags.begin());
+  }
 
-  return std::equal(new_flags.begin(), new_flags.end(), active_flags.begin());
+  if (out_difference && !result) {
+    std::set_symmetric_difference(
+        new_flags.begin(),
+        new_flags.end(),
+        active_flags.begin(),
+        active_flags.end(),
+        std::inserter(*out_difference, out_difference->begin()));
+  }
+
+  return result;
 }
 
 void GetFlagsExperimentsData(FlagsStorage* flags_storage,
                              FlagAccess access,
                              base::ListValue* supported_experiments,
                              base::ListValue* unsupported_experiments) {
   std::set<std::string> enabled_experiments;
   GetSanitizedEnabledFlags(flags_storage, &enabled_experiments);
 
   int current_platform = GetCurrentPlatform();
@@ skipping 87 matching lines @@
     action += *it;
     content::RecordComputedAction(action);
   }
   // Since flag metrics are recorded every startup, add a tick so that the
   // stats can be made meaningful.
   if (flags.size())
     content::RecordAction(UserMetricsAction("AboutFlags_StartupTick"));
   content::RecordAction(UserMetricsAction("StartupTick"));
 }
 
+void ReportCustomFlags(const std::string& uma_histogram_hame,
+                       const std::set<std::string>& command_line_difference) {
+  const about_flags::SwitchesHistogramIDs& switch_histogram_id_map =
+      about_flags::GetSwitchesHistogramIds();
+  for (std::set<std::string>::const_iterator it =
+           command_line_difference.begin();
+       it != command_line_difference.end();
+       ++it) {
+    int uma_id = about_flags::UMA_HISTOGRAM_ID_UNKNOWN_FLAG;
+    if (it->size() > 2) {
+      // Skip '--' before switch name.
+      std::string switch_name(it->substr(2));
+
+      // Kill value, if any.
+      const size_t value_pos = switch_name.find('=');
+      if (value_pos != std::string::npos)
+        switch_name.resize(value_pos);
+
+      const about_flags::SwitchesHistogramIDs::const_iterator pos =
+          switch_histogram_id_map.find(switch_name);
+      if (pos != switch_histogram_id_map.end()) {
+        uma_id = pos->second;
+      } else {
+        uma_id = about_flags::UMA_HISTOGRAM_ID_UNKNOWN_FLAG;
+        NOTREACHED() << "ReportCustomFlags(): flag '" << *it << "' ('"
+                     << switch_name << "') is unknown.";
+      }
+    } else {
+      uma_id = about_flags::UMA_HISTOGRAM_ID_BAD_FLAG_FORMAT;
+      NOTREACHED() << "ReportCustomFlags(): flag '" << *it
+                   << "' has incorrect format.";
+    }
+    VLOG(1) << "ReportCustomFlags(): histogram='" << uma_histogram_hame << "' '"
+            << *it << "', uma_id=" << uma_id;
+
+    // Sparse histogram macro does not cache the histogram, so it's safe
+    // to use macro with non-static histogram name here.
+    UMA_HISTOGRAM_SPARSE_SLOWLY(uma_histogram_hame, uma_id);
+  }
+}
+
 //////////////////////////////////////////////////////////////////////////////
 // FlagsState implementation.
 
 namespace {
 
 typedef std::map<std::string, std::pair<std::string, std::string> >
     NameToSwitchAndValueMap;
 
 void SetFlagToSwitchMapping(const std::string& key,
                             const std::string& switch_name,
@@ skipping 64 matching lines @@
     flags_switches_[switch_and_value_pair.first] = switch_and_value_pair.second;
   }
   if (sentinels == kAddSentinels) {
     command_line->AppendSwitch(switches::kFlagSwitchesEnd);
     flags_switches_.insert(
         std::pair<std::string, std::string>(switches::kFlagSwitchesEnd,
                                             std::string()));
   }
 }
 
+void SetSwitchToHistogramIdMapping(const std::string& switch_name,
+                                   const int switch_histogram_id,
+                                   std::map<std::string, int>* out_map) {
+  const std::pair<std::map<std::string, int>::iterator, bool> status =
+      out_map->insert(std::make_pair(switch_name, switch_histogram_id));
+  DCHECK(status.second || status.first->second == switch_histogram_id);
+}
+
+const SwitchesHistogramIDs& FlagsState::GetSwitchesHistogramIds() {
+  if (!switches_histogram_id_.empty())
+    return switches_histogram_id_;
+
+  for (size_t i = 0; i < num_experiments; ++i) {
+    const Experiment& e = experiments[i];
+    if (e.type == Experiment::SINGLE_VALUE) {
+      SetSwitchToHistogramIdMapping(e.command_line_switch,
+                                    e.command_line_switch_histogram_id,
+                                    &switches_histogram_id_);
+    } else if (e.type == Experiment::MULTI_VALUE) {
+      for (int j = 0; j < e.num_choices; ++j) {
+        SetSwitchToHistogramIdMapping(
+            e.choices[j].command_line_switch,
+            e.choices[j].command_line_switch_histogram_id,
+            &switches_histogram_id_);
+      }
+    } else {
+      DCHECK_EQ(e.type, Experiment::ENABLE_DISABLE_VALUE);
+      SetSwitchToHistogramIdMapping(e.command_line_switch,
+                                    e.command_line_switch_histogram_id,
+                                    &switches_histogram_id_);
+      SetSwitchToHistogramIdMapping(e.disable_command_line_switch,
+                                    e.disable_command_line_switch_histogram_id,
+                                    &switches_histogram_id_);
+    }
+  }
+  return switches_histogram_id_;
+}
+
 bool FlagsState::IsRestartNeededToCommitChanges() {
   return needs_restart_;
 }
 
 void FlagsState::SetExperimentEnabled(FlagsStorage* flags_storage,
                                       const std::string& internal_name,
                                       bool enable) {
   size_t at_index = internal_name.find(testing::kMultiSeparator);
   if (at_index != std::string::npos) {
     DCHECK(enable);
@@ skipping 95 matching lines @@
 }
 
 const Experiment* GetExperiments(size_t* count) {
   *count = num_experiments;
   return experiments;
 }
 
 }  // namespace testing
 
 }  // namespace about_flags