Add about_flag for experimenting MediaSession on Desktop

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 e9bf8c06ca6dcd15cc488b8922b7397aa0d27798..d3920c3c01ca3f362f344c66e980bf9987bb6c01 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -613,6 +613,17 @@ const FeatureEntry::Choice kDisableWebRtcHWEncodingChoices[] = {
 };
 #endif
 
+const FeatureEntry::Choice kEnableDefaultMediaSessionChoices[] = {
+    {IDS_FLAGS_ENABLE_DEFAULT_MEDIA_SESSION_DISABLED, "", ""},
+    {IDS_FLAGS_ENABLE_DEFAULT_MEDIA_SESSION_ENABLED,
+     switches::kEnableDefaultMediaSession, ""},
+#if defined(ENABLE_PLUGINS)
+    {IDS_FLAGS_ENABLE_DEFAULT_MEDIA_SESSION_ENABLED_WITH_FLASH,
+     switches::kEnableDefaultMediaSession,
+     switches::kEnableDefaultMediaSessionWithFlash},
+#endif  // defined(ENABLE_PLUGINS)
+};
+
 // RECORDING USER METRICS FOR FLAGS:
 // -----------------------------------------------------------------------------
 // The first line of the entry is the internal name.
@@ -2042,12 +2053,16 @@ const FeatureEntry kFeatureEntries[] = {
      IDS_FLAGS_EXPENSIVE_BACKGROUND_TIMER_THROTTLING_NAME,
      IDS_FLAGS_EXPENSIVE_BACKGROUND_TIMER_THROTTLING_DESCRIPTION, kOsAll,
      FEATURE_VALUE_TYPE(features::kExpensiveBackgroundTimerThrottling)},
-     {"security-chip", IDS_FLAGS_SECURITY_CHIP_NAME,
+    {"security-chip", IDS_FLAGS_SECURITY_CHIP_NAME,
      IDS_FLAGS_SECURITY_CHIP_DESCRIPTION, kOsDesktop,
      MULTI_VALUE_TYPE(kSecurityChipChoices)},
     {"security-chip-animation", IDS_FLAGS_SECURITY_CHIP_ANIMATION_NAME,
      IDS_FLAGS_SECURITY_CHIP_ANIMATION_DESCRIPTION, kOsDesktop,
      MULTI_VALUE_TYPE(kSecurityChipAnimationChoices)},
+    {"enable-default-media-session",
+     IDS_FLAGS_ENABLE_DEFAULT_MEDIA_SESSION_NAME,
+     IDS_FLAGS_ENABLE_DEFAULT_MEDIA_SESSION_DESCRIPTION, kOsDesktop,
+     MULTI_VALUE_TYPE(kEnableDefaultMediaSessionChoices)},
     // 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.