Fix multiple problems with omnibox text handling across focus changes.

chrome/browser/ui/cocoa/tabs/tab_strip_controller.mm

 // Copyright (c) 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/tabs/tab_strip_controller.h"
 
 #import <QuartzCore/QuartzCore.h>
 
 #include <cmath>
 #include <limits>
@@ skipping 1383 matching lines @@
   // selected tab to the top.
   [self layoutTabs];
 
   // Swap in the contents for the new tab.
   [self swapInTabAtIndex:modelIndex];
 
   if (newContents) {
     newContents->WasShown();
     newContents->GetView()->RestoreFocus();
   }
+
+  // The Browser expects a platform-specific TabStripModelObserver to call
+  // OnActiveTabChanged().
+  browser_->OnActiveTabChanged(oldContents, newContents, modelIndex, reason);
 }
 
 - (void)tabReplacedWithContents:(content::WebContents*)newContents
                previousContents:(content::WebContents*)oldContents
                         atIndex:(NSInteger)modelIndex {
   NSInteger index = [self indexFromModelIndex:modelIndex];
   TabContentsController* oldController =
       [tabContentsArray_ objectAtIndex:index];
   DCHECK_EQ(oldContents, [oldController webContents]);
 
@@ skipping 895 matching lines @@
 NSView* GetSheetParentViewForWebContents(WebContents* web_contents) {
   // View hierarchy of the contents view:
   // NSView  -- switchView, same for all tabs
   // +- NSView  -- TabContentsController's view
   //    +- TabContentsViewCocoa
   //
   // Changing it? Do not forget to modify
   // -[TabStripController swapInTabAtIndex:] too.
   return [web_contents->GetView()->GetNativeView() superview];
 }