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

chrome/browser/about_flags.cc

Index: chrome/browser/about_flags.cc
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index 5fcb4239f351221a9d1ed96adab5c4a3cc05bd52..a979408c53d0a550542a606f9430980288c10e6a 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -913,6 +913,16 @@ const FeatureEntry::FeatureVariation kDataReductionMainMenuFeatureVariations[] =
       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.
@@ -2759,6 +2769,10 @@ const FeatureEntry kFeatureEntries[] = {
      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.