Add key to focus infobars

On Windows & Chrome OS, pressing Alt+Shift+A will bring focus to the first
control in the first infobar, if any are shown. No reason for 'A' - 'I' is
already taken on Chrome OS, but all other hotkeys to directly focus a given
pane are Alt+Shift+Letter shortcuts.

BUG=226334

Review URL: https://chromiumcodereview.appspot.com/14225016

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@195030 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/browser/ui/browser_window.h b/chrome/browser/ui/browser_window.h
index b975952..b2755d815 100644
--- a/chrome/browser/ui/browser_window.h
+++ b/chrome/browser/ui/browser_window.h
@@ -162,6 +162,9 @@
   // Focuses the bookmarks toolbar (for accessibility).
   virtual void FocusBookmarksToolbar() = 0;
 
+  // Focuses an infobar, if shown (for accessibility).
+  virtual void FocusInfobars() = 0;
+
   // Moves keyboard focus to the next pane.
   virtual void RotatePaneFocus(bool forwards) = 0;