[Mac]Implement ViewID support.

chrome/browser/cocoa/tab_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/tab_view.h"
 
 #include "base/logging.h"
 #include "base/nsimage_cache_mac.h"
 #include "chrome/browser/browser_theme_provider.h"
 #import "chrome/browser/cocoa/tab_controller.h"
 #import "chrome/browser/cocoa/tab_window_controller.h"
 #import "chrome/browser/cocoa/themed_window.h"
+#import "chrome/browser/cocoa/view_id_util.h"
 #include "grit/theme_resources.h"
 
 namespace {
 
 // Constants for inset and control points for tab shape.
 const CGFloat kInsetMultiplier = 2.0/3.0;
 const CGFloat kControlPoint1Multiplier = 1.0/3.0;
 const CGFloat kControlPoint2Multiplier = 3.0/8.0;
 
 // The amount of time in seconds during which each type of glow increases, holds
@@ skipping 834 matching lines @@
       if ([child isKindOfClass:[NSButtonCell class]])
         [okChildren addObject:child];
     }
 
     return okChildren;
   }
 
   return [super accessibilityAttributeValue:attribute];
 }
 
+// Tag is used solely for ViewID. Override to prevent changing of it.
+- (NSInteger)tag {
+  return view_id_util::ViewIDToTag([controller_ viewID]);
+}
+
 @end  // @implementation TabView
 
 @implementation TabView (TabControllerInterface)
 
 - (void)setController:(TabController*)controller {
   controller_ = controller;
 }
 
 @end  // @implementation TabView (TabControllerInterface)
 
@@ skipping 80 matching lines @@
   }
 
   if (nextUpdate < kNoUpdate)
     [self performSelector:_cmd withObject:nil afterDelay:nextUpdate];
 
   [self resetLastGlowUpdateTime];
   [self setNeedsDisplay:YES];
 }
 
 @end  // @implementation TabView(Private)