Add method for identifying different InfoBars

components/infobars/core/infobar_delegate.h

Index: components/infobars/core/infobar_delegate.h
diff --git a/components/infobars/core/infobar_delegate.h b/components/infobars/core/infobar_delegate.h
index 7508de872cb569ebab1153ac967846559b5e3cfe..02d8fb7b3ad227a6dfdc84b3904e6d23c723cecf 100644
--- a/components/infobars/core/infobar_delegate.h
+++ b/components/infobars/core/infobar_delegate.h
@@ -60,6 +60,65 @@ class InfoBarDelegate {
     UNKNOWN_INFOBAR,
   };
 
+  // Unique identifier for every InfoBarDelegate subclass.
+  // KEEP IN SYNC WITH THE InfoBarIdentifier ENUM IN histograms.xml.
+  // NEW VALUES MUST BE APPENDED AND AVOID CHANGING ANY PRE-EXISTING VALUES.
+  enum InfoBarIdentifier {
+    INVALID_ID,

[Peter Kasting, 2015/12/30 01:52:57]

I'm inclined to remove "_ID" from every item as I'm not sure it adds anything
other than verbosity.

[gone, 2015/12/30 07:29:03]

Done.

+    TEST_INFOBAR_ID,

[Peter Kasting, 2015/12/30 01:52:57]

What do you think about putting an explicit "= n" on the end of each item, so
one can cross-reference more easily to the histogram, and so we can more easily
remove dead values in the future?

[gone, 2015/12/30 07:29:03]

Sounds good.  Alleviates a few of my concerns about the values getting out of
sync, too.

+    APP_BANNER_INFOBAR_DELEGATE_ANDROID_ID,
+    APP_BANNER_INFOBAR_DELEGATE_DESKTOP_ID,
+    ANDROID_DOWNLOAD_MANAGER_OVERWRITE_INFOBAR_DELEGATE_ID,
+    CHROME_DOWNLOAD_MANAGER_OVERWRITE_INFOBAR_DELEGATE_ID,
+    DOWNLOAD_REQUEST_INFOBAR_DELEGATE_ANDROID_ID,
+    FULLSCREEN_INFOBAR_DELEGATE_ID,
+    HUNG_PLUGIN_INFOBAR_DELEGATE_ID,
+    HUNG_RENDERER_INFOBAR_DELEGATE_ID,
+    MEDIA_STREAM_INFOBAR_DELEGATE_ANDROID_ID,
+    MEDIA_THROTTLE_INFOBAR_DELEGATE_ID,
+    REQUEST_QUOTA_INFOBAR_DELEGATE_ID,
+    DEV_TOOLS_CONFIRM_INFOBAR_DELEGATE_ID,
+    EXTENSION_DEV_TOOLS_INFOBAR_DELEGATE_ID,
+    INCOGNITO_CONNECTABILITY_INFOBAR_DELEGATE_ID,
+    THEME_INSTALLED_INFOBAR_DELEGATE_ID,
+    GEOLOCATION_INFOBAR_DELEGATE_ANDROID_ID,
+    THREE_D_API_INFOBAR_DELEGATE_ID,
+    INSECURE_CONTENT_INFOBAR_DELEGATE_ID,
+    MIDI_PERMISSION_INFOBAR_DELEGATE_ANDROID_ID,
+    PROTECTED_MEDIA_IDENTIFIER_INFOBAR_DELEGATE_ANDROID_ID,
+    NACL_INFOBAR_DELEGATE_ID,
+    DATA_REDUCTION_PROXY_INFOBAR_DELEGATE_ANDROID_ID,
+    NOTIFICATION_PERMISSION_INFOBAR_DELEGATE_ID,
+    AUTO_SIGNIN_FIRST_RUN_INFOBAR_DELEGATE_ID,
+    GENERATED_PASSWORD_SAVED_INFOBAR_DELEGATE_ANDROID_ID,
+    SAVE_PASSWORD_INFOBAR_DELEGATE_ID,
+    PEPPER_BROKER_INFOBAR_DELEGATE_ID,
+    PERMISSION_UPDATE_INFOBAR_DELEGATE_ID,
+    DURABLE_STORAGE_PERMISSION_INFOBAR_DELEGATE_ANDROID_ID,
+    NPAPI_REMOVAL_INFOBAR_DELEGATE_ID,
+    OUTDATED_PLUGIN_INFOBAR_DELEGATE_ID,
+    PLUGIN_METRO_MODE_INFOBAR_DELEGATE_ID,
+    RELOAD_PLUGIN_INFOBAR_DELEGATE_ID,
+    PLUGIN_OBSERVER_ID,
+    SSL_ADD_CERTIFICATE_ID,
+    SSL_ADD_CERTIFICATE_INFOBAR_DELEGATE_ID,
+    POPUP_BLOCKED_INFOBAR_DELEGATE_ID,
+    CHROME_SELECT_FILE_POLICY_ID,
+    KEYSTONE_PROMOTION_INFOBAR_DELEGATE_ID,
+    COLLECTED_COOKIES_INFOBAR_DELEGATE_ID,
+    INSTALLATION_ERROR_INFOBAR_DELEGATE_ID,
+    ALTERNATE_NAV_INFOBAR_DELEGATE_ID,
+    BAD_FLAGS_PROMPT_ID,
+    DEFAULT_BROWSER_INFOBAR_DELEGATE_ID,
+    GOOGLE_API_KEYS_INFOBAR_DELEGATE_ID,
+    OBSOLETE_SYSTEM_INFOBAR_DELEGATE_ID,
+    SESSION_CRASHED_INFOBAR_DELEGATE_ID,
+    WEBSITE_SETTINGS_INFOBAR_DELEGATE_ID,
+    AUTOFILL_CC_INFOBAR_DELEGATE_ID,
+    TRANSLATE_INFOBAR_DELEGATE_ID,
+    IOS_CHROME_SAVE_PASSWORD_INFOBAR_DELEGATE_ID
+  };
+
   // Describes navigation events, used to decide whether infobars should be
   // dismissed.
   struct NavigationDetails {
@@ -84,6 +143,11 @@ class InfoBarDelegate {
   // as background color) of the infobar.
   virtual Type GetInfoBarType() const;
 
+  // Returns a unique value identifying the infobar.
+  // New implementers must append a new value to the InfoBarIdentifier enum here
+  // and in histograms.xml.
+  virtual InfoBarIdentifier GetIdentifier() const = 0;
+
   virtual InfoBarAutomationType GetInfoBarAutomationType() const;
 
   // Returns the resource ID of the icon to be shown for this InfoBar.  If the