Add memory ablation experiment.

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/bind.h"
 #include "base/callback.h"
 #include "base/command_line.h"
 #include "base/feature_list.h"
 #include "base/i18n/base_i18n_switches.h"
 #include "base/macros.h"
 #include "base/memory/singleton.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/metrics/metrics_hashes.h"
 #include "base/stl_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/task_scheduler/switches.h"
 #include "base/values.h"
 #include "build/build_config.h"
 #include "cc/base/switches.h"
+#include "chrome/browser/experiments/memory_ablation_experiment.h"
 #include "chrome/browser/flag_descriptions.h"
 #include "chrome/browser/ntp_snippets/ntp_snippets_features.h"
 #include "chrome/browser/page_load_metrics/experiments/delay_navigation_throttle.h"
 #include "chrome/browser/predictors/resource_prefetch_common.h"
 #include "chrome/browser/prerender/prerender_field_trial.h"
 #include "chrome/common/channel_info.h"
 #include "chrome/common/chrome_content_client.h"
 #include "chrome/common/chrome_features.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/features.h"
@@ skipping 782 matching lines @@
     {DelayNavigationThrottle::kParamDelayNavigationRandomize, "true"}};
 
 const FeatureEntry::FeatureVariation kDelayNavigationFeatureVariations[] = {
     {"(5 second delay, 100% probability)", kDelayNavigation5SecondDelay,
      arraysize(kDelayNavigation5SecondDelay), nullptr},
     {"(5 second delay, 25% probability)", kDelayNavigation5SecondDelay25Percent,
      arraysize(kDelayNavigation5SecondDelay25Percent), nullptr},
     {"(0-5 second randomized delay)", kDelayNavigation5SecondDelayRandomize,
      arraysize(kDelayNavigation5SecondDelayRandomize), nullptr}};
 
+const FeatureEntry::FeatureParam kMemoryAblation1MiB[] = {
+    {kMemoryAblationFeatureSizeParam, "1048576"}};
+const FeatureEntry::FeatureParam kMemoryAblation2MiB[] = {
+    {kMemoryAblationFeatureSizeParam, "2097152"}};
+const FeatureEntry::FeatureParam kMemoryAblation5MiB[] = {
+    {kMemoryAblationFeatureSizeParam, "5242880"}};
+const FeatureEntry::FeatureParam kMemoryAblation10MiB[] = {
+    {kMemoryAblationFeatureSizeParam, "10485760"}};
+
+const FeatureEntry::FeatureVariation kMemoryAblationFeatureVariations[] = {
+    {"1 MiB", kMemoryAblation1MiB, arraysize(kMemoryAblation1MiB), nullptr},
+    {"2 MiB", kMemoryAblation2MiB, arraysize(kMemoryAblation2MiB), nullptr},
+    {"5 MiB", kMemoryAblation5MiB, arraysize(kMemoryAblation5MiB), nullptr},

[Primiano Tucci (use gerrit), 2017/04/10 18:05:04]

I think 2 vs 5 isn't going to be a huge difference, maybe these should be a bit
more esponential, like, 1, 5, 10, 100 ?

[DmitrySkiba, 2017/04/10 19:30:59]

Done. Removed 2, added 50. These values are just for the chrome://flags, we can
use any values in the experiment.

+    {"10 MiB", kMemoryAblation10MiB, arraysize(kMemoryAblation10MiB), nullptr}};
+
 #if defined(OS_ANDROID)
 const FeatureEntry::FeatureParam kPersistentMenuItemEnabled[] = {
     {"persistent_menu_item_enabled", "true"}};
 
 const FeatureEntry::FeatureVariation kDataReductionMainMenuFeatureVariations[] =
     {{"(persistent)", kPersistentMenuItemEnabled,
       arraysize(kPersistentMenuItemEnabled), nullptr}};
 #endif  // OS_ANDROID
 
 // RECORDING USER METRICS FOR FLAGS:
@@ skipping 1743 matching lines @@
                                     kUseNewDoodleApiVariations,
                                     chrome::android::kUseNewDoodleApi.name)},
 #endif  // OS_ANDROID
 
     {"delay-navigation", flag_descriptions::kDelayNavigationName,
      flag_descriptions::kDelayNavigationDescription, kOsAll,
      FEATURE_WITH_PARAMS_VALUE_TYPE(kDelayNavigationFeature,
                                     kDelayNavigationFeatureVariations,
                                     "DelayNavigation")},
 
+    {"memory-ablation", flag_descriptions::kMemoryAblationName,
+     flag_descriptions::kMemoryAblationDescription, kOsAll,
+     FEATURE_WITH_PARAMS_VALUE_TYPE(kMemoryAblationFeature,
+                                    kMemoryAblationFeatureVariations,
+                                    "MemoryAblation")},
+
 #if defined(OS_ANDROID)
     {"enable-custom-context-menu",
      flag_descriptions::kEnableCustomContextMenuName,
      flag_descriptions::kEnableCustomContextMenuDescription, kOsAndroid,
      FEATURE_VALUE_TYPE(chrome::android::kCustomContextMenu)},
 #endif  // OS_ANDROID
 
 #if defined(USE_ASH)
     {"ash-enable-smooth-screen-rotation",
      flag_descriptions::kAshEnableSmoothScreenRotationName,
      flag_descriptions::kAshEnableSmoothScreenRotationDescription, kOsCrOS,
      SINGLE_VALUE_TYPE(ash::switches::kAshEnableSmoothScreenRotation)},
 #endif  // defined(USE_ASH)
 
 #if defined(OS_CHROMEOS)
     {"enable-zip-archiver-on-file-manager",
      flag_descriptions::kEnableZipArchiverOnFileManagerName,
-     flag_descriptions::kEnableZipArchiverOnFileManagerDescription,

[DmitrySkiba, 2017/04/10 17:15:42]

This was formatted by "git cl format" along with my changes.

-     kOsCrOS,
-     SINGLE_VALUE_TYPE(
-         chromeos::switches::kEnableZipArchiverOnFileManager)},
+     flag_descriptions::kEnableZipArchiverOnFileManagerDescription, kOsCrOS,
+     SINGLE_VALUE_TYPE(chromeos::switches::kEnableZipArchiverOnFileManager)},
 #endif  // OS_CHROMEOS
 
     // NOTE: Adding new command-line switches requires adding corresponding
     // entries to enum "LoginCustomFlags" in histograms.xml. See note in
     // histograms.xml and don't forget to run AboutFlagsHistogramTest unit test.
 };
 
 class FlagsStateSingleton {
  public:
   FlagsStateSingleton()
@@ skipping 198 matching lines @@
 const base::HistogramBase::Sample kBadSwitchFormatHistogramId = 0;
 
 const FeatureEntry* GetFeatureEntries(size_t* count) {
   *count = arraysize(kFeatureEntries);
   return kFeatureEntries;
 }
 
 }  // namespace testing
 
 }  // namespace about_flags