Activate scrollbars (etc.) upon selecting a tab....

chrome/browser/tab_contents/tab_contents.cc

 // Copyright (c) 2009 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.
 
 #include "chrome/browser/tab_contents/tab_contents.h"
 
 #include "app/l10n_util.h"
 #include "app/resource_bundle.h"
 #include "base/file_version_info.h"
 #include "base/process_util.h"
@@ skipping 582 matching lines @@
 }
 
 void TabContents::NotifyNavigationStateChanged(unsigned changed_flags) {
   if (delegate_)
     delegate_->NavigationStateChanged(this, changed_flags);
 }
 
 void TabContents::DidBecomeSelected() {
   controller_.SetActive(true);
 
-  if (render_widget_host_view())
+  if (render_widget_host_view()) {
     render_widget_host_view()->DidBecomeSelected();
+#if defined(OS_MACOSX)
+    render_widget_host_view()->SetActive(true);
+#endif
+  }
 
   // If pid() is -1, that means the RenderProcessHost still hasn't been
   // initialized.  It'll register with CacheManagerHost when it is.
   if (process()->pid() != -1)
     WebCacheManager::GetInstance()->ObserveActivity(process()->pid());
 }
 
 void TabContents::WasHidden() {
   if (!capturing_contents()) {
     // |render_view_host()| can be NULL if the user middle clicks a link to open
@@ skipping 1762 matching lines @@
       NavigationController::LoadCommittedDetails& committed_details =
           *(Details<NavigationController::LoadCommittedDetails>(details).ptr());
       ExpireInfoBars(committed_details);
       break;
     }
 
     default:
       NOTREACHED();
   }
 }