[Mac]Implement ViewID support. (third approach)

chrome/browser/cocoa/extensions/browser_actions_container_view.mm

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "chrome/browser/cocoa/extensions/browser_actions_container_view.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #import "base/scoped_nsobject.h"
+#import "chrome/browser/cocoa/view_id_util.h"
 
 NSString* const kBrowserActionGrippyDragStartedNotification =
     @"BrowserActionGrippyDragStartedNotification";
 NSString* const kBrowserActionGrippyDraggingNotification =
     @"BrowserActionGrippyDraggingNotification";
 NSString* const kBrowserActionGrippyDragFinishedNotification =
     @"BrowserActionGrippyDragFinishedNotification";
 
 namespace {
 const CGFloat kAnimationDuration = 0.2;
@@ skipping 131 matching lines @@
   [self setFrame:containerFrame];
   [self setNeedsDisplay:YES];
 
   [[NSNotificationCenter defaultCenter]
       postNotificationName:kBrowserActionGrippyDraggingNotification
                     object:self];
 
   lastXPos_ += dX;
 }
 
+- (ViewID)viewID {
+  return VIEW_ID_BROWSER_ACTION_TOOLBAR;
+}
+
 #pragma mark -
 #pragma mark Public Methods
 
 - (void)resizeToWidth:(CGFloat)width animate:(BOOL)animate {
   width = std::max(width, kMinimumContainerWidth);
   NSRect frame = [self frame];
   lastXPos_ = frame.origin.x;
   CGFloat dX = frame.size.width - width;
   frame.size.width = width;
   NSRect newFrame = NSOffsetRect(frame, dX, 0);
@@ skipping 26 matching lines @@
     retVal = [NSCursor resizeRightCursor];
   } else if (!canDragRight_) {
     retVal = [NSCursor resizeLeftCursor];
   } else {
     retVal = [NSCursor resizeLeftRightCursor];
   }
   return retVal;
 }
 
 @end