mac: Fix tab dragging visual bug in Yosemite.

chrome/browser/ui/cocoa/browser_window_controller.mm

 // Copyright 2012 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/ui/cocoa/browser_window_controller.h"
 
 #include <cmath>
 #include <numeric>
 
 #include "base/command_line.h"
@@ skipping 1538 matching lines @@
 
 - (BOOL)isDownloadShelfVisible {
   return downloadShelfController_ != nil &&
       [downloadShelfController_ isVisible];
 }
 
 - (DownloadShelfController*)downloadShelf {
   if (!downloadShelfController_.get()) {
     downloadShelfController_.reset([[DownloadShelfController alloc]
         initWithBrowser:browser_.get() resizeDelegate:self]);
-    [[[self window] contentView] addSubview:[downloadShelfController_ view]];
+    [self.chromeContentView addSubview:[downloadShelfController_ view]];
   }
   return downloadShelfController_;
 }
 
 - (void)addFindBar:(FindBarCocoaController*)findBarCocoaController {
   // Shouldn't call addFindBar twice.
   DCHECK(!findBarCocoaController_.get());
 
   // Create a controller for the findbar.
   findBarCocoaController_.reset([findBarCocoaController retain]);
@@ skipping 721 matching lines @@
 
 - (BOOL)supportsBookmarkBar {
   return [self supportsWindowFeature:Browser::FEATURE_BOOKMARKBAR];
 }
 
 - (BOOL)isTabbedWindow {
   return browser_->is_type_tabbed();
 }
 
 @end  // @implementation BrowserWindowController(WindowType)