[Mac]Implement ViewID support.

chrome/browser/cocoa/toolbar_controller.mm

Index: chrome/browser/cocoa/toolbar_controller.mm
diff --git a/chrome/browser/cocoa/toolbar_controller.mm b/chrome/browser/cocoa/toolbar_controller.mm
index 1a3bc74347b82a6e2341a67b41f04b39ee8e70d8..92eccc6f248c36447ffee420e9df222399b9986f 100644
--- a/chrome/browser/cocoa/toolbar_controller.mm
+++ b/chrome/browser/cocoa/toolbar_controller.mm
@@ -31,6 +31,7 @@
 #import "chrome/browser/cocoa/menu_controller.h"
 #import "chrome/browser/cocoa/reload_button.h"
 #import "chrome/browser/cocoa/toolbar_view.h"
+#import "chrome/browser/cocoa/view_id_util.h"
 #include "chrome/browser/net/url_fixer_upper.h"
 #include "chrome/browser/pref_service.h"
 #include "chrome/browser/profile.h"
@@ -295,6 +296,20 @@ class PrefObserverBridge : public NotificationObserver {
          selector:@selector(toolbarFrameChanged)
              name:NSViewFrameDidChangeNotification
            object:toolbarView];
+
+  // Set commands for toolbar buttons. |reloadButton_| sets it by itself.
+  [backButton_ setCommand:IDC_BACK];
+  [forwardButton_ setCommand:IDC_FORWARD];
+  [homeButton_ setCommand:IDC_HOME];
+  [wrenchButton_ setCommand:IDC_SHOW_APP_MENU];
+
+  // Set View IDs for toolbar elements. It's not necessary for |reloadButton_|,
+  // |locationBar_| and |browserActionsContainerView_|, which override NSView's
+  // tag method directly.
+  [backButton_ setViewID:VIEW_ID_BACK_BUTTON];
+  [forwardButton_ setViewID:VIEW_ID_FORWARD_BUTTON];
+  [homeButton_ setViewID:VIEW_ID_HOME_BUTTON];
+  [wrenchButton_ setViewID:VIEW_ID_APP_MENU];
 }
 
 - (void)addAccessibilityDescriptions {
@@ -698,8 +713,8 @@ class PrefObserverBridge : public NotificationObserver {
          userData:(void*)userData {
   DCHECK(view == reloadButton_);
 
-  return l10n_util::GetNSStringWithFixup(
-      [reloadButton_ tag] == IDC_STOP ? IDS_TOOLTIP_STOP : IDS_TOOLTIP_RELOAD);
+  return l10n_util::GetNSStringWithFixup([reloadButton_ command] == IDC_STOP ?
+      IDS_TOOLTIP_STOP : IDS_TOOLTIP_RELOAD);
 }
 
 // (URLDropTargetController protocol)