Add support for a "frame" context option to chrome.contextMenus.create/update.

Also removes a couple of .html files from the "simple" context menu browser
test, since they weren't needed.

Includes documentation update for http://trac.webkit.org/changeset/83033.

BUG=49783
TEST=ExtensionContextMenuBrowserTest.Frames
[email protected]

Review URL: http://codereview.chromium.org/6799020

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@80692 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/browser/extensions/extension_menu_manager.h b/chrome/browser/extensions/extension_menu_manager.h
index 94cbe755..e9bb36d 100644
--- a/chrome/browser/extensions/extension_menu_manager.h
+++ b/chrome/browser/extensions/extension_menu_manager.h
@@ -58,6 +58,7 @@
     IMAGE = 32,
     VIDEO = 64,
     AUDIO = 128,
+    FRAME = 256,
   };
 
   // An item can be only one of these types.