Initialize GPU shader disk cache on brower thread.

content/public/browser/content_browser_client.cc

 // 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.
 
 #include "content/public/browser/content_browser_client.h"
 
 #include "base/files/file_path.h"
 #include "content/public/browser/client_certificate_delegate.h"
 #include "content/public/common/sandbox_type.h"
 #include "ui/gfx/image/image_skia.h"
@@ skipping 267 matching lines @@
 }
 
 base::FilePath ContentBrowserClient::GetDefaultDownloadDirectory() {
   return base::FilePath();
 }
 
 std::string ContentBrowserClient::GetDefaultDownloadName() {
   return std::string();
 }
 
+base::FilePath ContentBrowserClient::GetShaderDiskCacheDirectory() {
+  return base::FilePath();
+}
+
 BrowserPpapiHost*
     ContentBrowserClient::GetExternalBrowserPpapiHost(int plugin_process_id) {
   return nullptr;
 }
 
 bool ContentBrowserClient::AllowPepperSocketAPI(
     BrowserContext* browser_context,
     const GURL& url,
     bool private_api,
     const SocketPermissionRequest* params) {
@@ skipping 65 matching lines @@
 #if defined(VIDEO_HOLE)
 ExternalVideoSurfaceContainer*
 ContentBrowserClient::OverrideCreateExternalVideoSurfaceContainer(
     WebContents* web_contents) {
   NOTREACHED() << "Hole-punching is not supported. See crbug.com/469348.";
   return nullptr;
 }
 #endif
 
 }  // namespace content