Remove unused ContentBrowserClient::IsFastShutdownPossible.

chrome/browser/chrome_content_browser_client.h

 // 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.
 
 #ifndef CHROME_BROWSER_CHROME_CONTENT_BROWSER_CLIENT_H_
 #define CHROME_BROWSER_CHROME_CONTENT_BROWSER_CLIENT_H_
 
 #include <stddef.h>
 
 #include <memory>
@@ skipping 192 matching lines @@
                        bool opener_suppressed,
                        content::ResourceContext* context,
                        int render_process_id,
                        int opener_render_view_id,
                        int opener_render_frame_id,
                        bool* no_javascript_access) override;
   void ResourceDispatcherHostCreated() override;
   content::SpeechRecognitionManagerDelegate*
   CreateSpeechRecognitionManagerDelegate() override;
   net::NetLog* GetNetLog() override;
-
-  bool IsFastShutdownPossible() override;
   void OverrideWebkitPrefs(content::RenderViewHost* rvh,
                            content::WebPreferences* prefs) override;
   void BrowserURLHandlerCreated(content::BrowserURLHandler* handler) override;
   void ClearCache(content::RenderFrameHost* rfh) override;
   void ClearCookies(content::RenderFrameHost* rfh) override;
   base::FilePath GetDefaultDownloadDirectory() override;
   std::string GetDefaultDownloadName() override;
   base::FilePath GetShaderDiskCacheDirectory() override;
   void DidCreatePpapiPlugin(content::BrowserPpapiHost* browser_host) override;
   content::BrowserPpapiHost* GetExternalBrowserPpapiHost(
@@ skipping 120 matching lines @@
   // Vector of additional ChromeContentBrowserClientParts.
   // Parts are deleted in the reverse order they are added.
   std::vector<ChromeContentBrowserClientParts*> extra_parts_;
 
   base::WeakPtrFactory<ChromeContentBrowserClient> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeContentBrowserClient);
 };
 
 #endif  // CHROME_BROWSER_CHROME_CONTENT_BROWSER_CLIENT_H_