ui: Add debug flag to show composited layer borders in ChromeOS UI.

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 d1d8ace65391c7f5c9940ad3922506eb69165f06..3771ff5e763f46669a7ec2d16ad16616aac46292 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -436,6 +436,17 @@ const FeatureEntry::Choice kDataSaverPromptChoices[] = {
      chromeos::switches::kEnableDataSaverPrompt,
      chromeos::switches::kDataSaverPromptDemoMode},
 };
+
+const FeatureEntry::Choice kUiShowCompositedLayerBordersChoices[] = {
+    {flags_ui::kGenericExperimentChoiceDefault, "", ""},
+    {flag_descriptions::kUiShowCompositedLayerBordersRenderpass,
+     cc::switches::kUIShowCompositedLayerBorders, "renderpass"},

[danakj, 2017/04/13 15:25:51]

should we introduce constants for these parameters? (maybe not for the all ""
case tho)

[reveman, 2017/04/13 17:00:46]

Done.

+    {flag_descriptions::kUiShowCompositedLayerBordersSurface,
+     cc::switches::kUIShowCompositedLayerBorders, "surface"},
+    {flag_descriptions::kUiShowCompositedLayerBordersLayer,
+     cc::switches::kUIShowCompositedLayerBorders, "layer"},
+    {flag_descriptions::kUiShowCompositedLayerBordersAll,
+     cc::switches::kUIShowCompositedLayerBorders, "renderpass,surface,layer"}};

[danakj, 2017/04/13 15:25:51]

maybe just make this "" and empty => all?

[reveman, 2017/04/13 17:00:46]

Done.

 #endif  // OS_CHROMEOS
 
 const FeatureEntry::Choice kV8CacheOptionsChoices[] = {
@@ -1167,6 +1178,10 @@ const FeatureEntry kFeatureEntries[] = {
     {"ui-slow-animations", flag_descriptions::kUiSlowAnimationsName,
      flag_descriptions::kUiSlowAnimationsDescription, kOsCrOS,
      SINGLE_VALUE_TYPE(switches::kUISlowAnimations)},
+    {"ui-show-composited-layer-borders",
+     flag_descriptions::kUiShowCompositedLayerBordersName,
+     flag_descriptions::kUiShowCompositedLayerBordersDescription, kOsCrOS,
+     MULTI_VALUE_TYPE(kUiShowCompositedLayerBordersChoices)},
     {"disable-cloud-import", flag_descriptions::kCloudImport,
      flag_descriptions::kCloudImportDescription, kOsCrOS,
      SINGLE_DISABLE_VALUE_TYPE(chromeos::switches::kDisableCloudImport)},