[tracing] Allow enabling heap profiling from chrome://flags

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>
@@ skipping 895 matching lines @@
 
 #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
 
+const FeatureEntry::Choice kEnableHeapProfilingChoices[] = {
+    {flags_ui::kGenericExperimentChoiceDisabled, "", ""},
+    {flag_descriptions::kEnableHeapProfilingModePseudo,
+     switches::kEnableHeapProfiling, switches::kEnableHeapProfilingModePseudo},
+    {flag_descriptions::kEnableHeapProfilingModeNative,
+     switches::kEnableHeapProfiling, switches::kEnableHeapProfilingModeNative},
+    {flag_descriptions::kEnableHeapProfilingTaskProfiler,
+     switches::kEnableHeapProfiling,
+     switches::kEnableHeapProfilingTaskProfiler}};
+
 // RECORDING USER METRICS FOR FLAGS:
 // -----------------------------------------------------------------------------
 // The first line of the entry is the internal name.
 //
 // To add a new entry, add to the end of kFeatureEntries. There are two
 // distinct types of entries:
 // . SINGLE_VALUE: entry is either on or off. Use the SINGLE_VALUE_TYPE
 //   macro for this type supplying the command line to the macro.
 // . MULTI_VALUE: a list of choices, the first of which should correspond to a
 //   deactivated state for this lab (i.e. no command line option).  To specify
@@ skipping 1826 matching lines @@
     {"enable-clipboard-provider",
      flag_descriptions::kEnableOmniboxClipboardProviderName,
      flag_descriptions::kEnableOmniboxClipboardProviderDescription, kOsAndroid,
      FEATURE_VALUE_TYPE(omnibox::kEnableClipboardProvider)},
 #endif
 
     {"autoplay-policy", flag_descriptions::kAutoplayPolicyName,
      flag_descriptions::kAutoplayPolicyDescription, kOsAll,
      MULTI_VALUE_TYPE(kAutoplayPolicyChoices)},
 
+    {"enable-heap-profiling", flag_descriptions::kEnableHeapProfilingName,
+     flag_descriptions::kEnableHeapProfilingDescription, kOsAll,
+     MULTI_VALUE_TYPE(kEnableHeapProfilingChoices)},
+
     // 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()
       : flags_state_(kFeatureEntries, arraysize(kFeatureEntries)) {}
   ~FlagsStateSingleton() {}
@@ skipping 205 matching lines @@
 const base::HistogramBase::Sample kBadSwitchFormatHistogramId = 0;
 
 const FeatureEntry* GetFeatureEntries(size_t* count) {
   *count = arraysize(kFeatureEntries);
   return kFeatureEntries;
 }
 
 }  // namespace testing
 
 }  // namespace about_flags