Make gpu black list work again on Linux

content/browser/gpu/gpu_data_manager_impl.h

 // Copyright (c) 2013 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 CONTENT_BROWSER_GPU_GPU_DATA_MANAGER_IMPL_H_
 #define CONTENT_BROWSER_GPU_GPU_DATA_MANAGER_IMPL_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 45 matching lines @@
     DOMAIN_BLOCK_STATUS_ALL_DOMAINS_BLOCKED,
     DOMAIN_BLOCK_STATUS_NOT_BLOCKED
   };
 
   // Getter for the singleton. This will return NULL on failure.
   static GpuDataManagerImpl* GetInstance();
 
   // GpuDataManager implementation.
   void InitializeForTesting(const std::string& gpu_blacklist_json,
                             const gpu::GPUInfo& gpu_info) override;
+  bool IsInitialized() const override;
   bool IsFeatureBlacklisted(int feature) const override;
   gpu::GPUInfo GetGPUInfo() const override;
   void GetGpuProcessHandles(
       const GetGpuProcessHandlesCallback& callback) const override;
   bool GpuAccessAllowed(std::string* reason) const override;
   void RequestCompleteGpuInfoIfNeeded() override;
   bool IsEssentialGpuInfoAvailable() const override;
   bool IsCompleteGpuInfoAvailable() const override;
   void RequestVideoMemoryUsageStatsUpdate() const override;
   bool ShouldUseSwiftShader() const override;
@@ skipping 143 matching lines @@
 
   mutable base::Lock lock_;
   scoped_ptr<GpuDataManagerImplPrivate> private_;
 
   DISALLOW_COPY_AND_ASSIGN(GpuDataManagerImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_GPU_GPU_DATA_MANAGER_IMPL_H_