Add UMA metrics for Bookmark widgets.

chrome/browser/android/shortcut_info.h

Index: chrome/browser/android/shortcut_info.h
diff --git a/chrome/browser/android/shortcut_info.h b/chrome/browser/android/shortcut_info.h
index 3b0d01fa61fbcbc80cc98fcbb0c52424db394f51..c53f071abe2d18b792e60b02d030b27e3d743559 100644
--- a/chrome/browser/android/shortcut_info.h
+++ b/chrome/browser/android/shortcut_info.h
@@ -15,11 +15,15 @@ struct ShortcutInfo {
 
   // This enum is used to back a UMA histogram, and must be treated as
   // append-only.
+  // A Java counterpart will be generated for this enum.
+  // GENERATED_JAVA_ENUM_PACKAGE: org.chromium.chrome.browser

[newt (away), 2015/07/15 02:56:00]

Source is a very generic name. Let's generate the Java enum into something more
explicit, say, ShortcutSource. You can do this by adding another tag like
GENERATED_JAVA_ENUM_PACKAGE. See java_cpp_enum_tests.py for examples:
https://code.google.com/p/chromium/codesearch#chromium/src/build/android/gyp/...

[aurimas (slooooooooow), 2015/07/16 01:15:31]

Done

[aurimas (slooooooooow), 2015/07/16 01:15:31]

Done

   enum Source {
     SOURCE_UNKNOWN = 0,
     SOURCE_ADD_TO_HOMESCREEN = 1,
     SOURCE_APP_BANNER = 2,
-    SOURCE_COUNT = 3
+    SOURCE_BOOKMARK_NAVIGATOR_WIDGET = 3,
+    SOURCE_BOOKMARK_SHORTCUT_WIDGET = 4,
+    SOURCE_COUNT = 5
   };
 
   ShortcutInfo();