Media Galleries API Scanning: Extension API stubs.

Contains the stubs for the extension functions, as well as the enum definitions necessary.

BUG=161119

Review URL: https://codereview.chromium.org/137853007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@245667 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/browser/extensions/extension_function_histogram_value.h b/chrome/browser/extensions/extension_function_histogram_value.h
index c14cb1a..8604615 100644
--- a/chrome/browser/extensions/extension_function_histogram_value.h
+++ b/chrome/browser/extensions/extension_function_histogram_value.h
@@ -722,6 +722,9 @@
   READINGLISTPRIVATE_ADDENTRY,
   READINGLISTPRIVATE_REMOVEENTRY,
   READINGLISTPRIVATE_GETENTRIES,
+  MEDIAGALLERIES_STARTMEDIASCAN,
+  MEDIAGALLERIES_CANCELMEDIASCAN,
+  MEDIAGALLERIES_ADDSCANRESULTS,
   ENUM_BOUNDARY // Last entry: Add new entries above.
 };