services/ui: Inject GpuService instance where needed, instead of singleton.

services/ui/common/gpu_service.h

 // Copyright 2016 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 SERVICES_UI_COMMON_GPU_SERVICE_H_
 #define SERVICES_UI_COMMON_GPU_SERVICE_H_
 
 #include <stdint.h>
 #include <vector>
 
@@ skipping 19 matching lines @@
  public:
   ~GpuService() override;
 
   gpu::GpuMemoryBufferManager* gpu_memory_buffer_manager() const {
     return gpu_memory_buffer_manager_.get();
   }
 
   // The GpuService has to be initialized in the main thread before establishing
   // the gpu channel.
   static std::unique_ptr<GpuService> Initialize(shell::Connector* connector);
-  static GpuService* GetInstance();
 
   // gpu::GpuChannelEstablishFactory:
   void EstablishGpuChannel(
       const gpu::GpuChannelEstablishedCallback& callback) override;
   scoped_refptr<gpu::GpuChannelHost> EstablishGpuChannelSync() override;
 
  private:
   friend struct base::DefaultSingletonTraits<GpuService>;
 
   explicit GpuService(shell::Connector* connector);
@@ skipping 26 matching lines @@
   scoped_refptr<gpu::GpuChannelHost> gpu_channel_;
   std::vector<gpu::GpuChannelEstablishedCallback> establish_callbacks_;
   base::ConditionVariable establishing_condition_;
 
   DISALLOW_COPY_AND_ASSIGN(GpuService);
 };
 
 }  // namespace ui
 
 #endif  // COMPONENTS_MUS_PUBLIC_CPP_LIB_GPU_SERVICE_CONNECTION_H_