overscroll: Allow taking screenshots only in tabbed browsers.

chrome/browser/ui/browser.cc

 // 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.
 
 #include "chrome/browser/ui/browser.h"
 
 #if defined(OS_WIN)
 #include <windows.h>
 #include <shellapi.h>
 #endif  // defined(OS_WIN)
@@ skipping 1142 matching lines @@
   MessageLoop::current()->PostTask(
       FROM_HERE, base::Bind(&Browser::CloseFrame, weak_factory_.GetWeakPtr()));
 
   // Instant may have visible WebContents that need to be detached before the
   // window system closes.
   instant_controller_.reset();
 }
 
 bool Browser::CanOverscrollContent() const {
 #if defined(USE_AURA)
-  return true;
+  return !is_app() && !is_devtools() && is_type_tabbed();
 #else
   return false;
 #endif
 }
 
 bool Browser::PreHandleKeyboardEvent(content::WebContents* source,
                                      const NativeWebKeyboardEvent& event,
                                      bool* is_keyboard_shortcut) {
   // Escape exits tabbed fullscreen mode.
   // TODO(koz): Write a test for this http://crbug.com/100441.
@@ skipping 1158 matching lines @@
   if (contents && !allow_js_access) {
     contents->web_contents()->GetController().LoadURL(
         target_url,
         content::Referrer(),
         content::PAGE_TRANSITION_LINK,
         std::string());  // No extra headers.
   }
 
   return contents != NULL;
 }