Remove ContextProvider::IsContextLost.

cc/test/test_in_process_context_provider.h

 // Copyright 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 CC_TEST_TEST_IN_PROCESS_CONTEXT_PROVIDER_H_
 #define CC_TEST_TEST_IN_PROCESS_CONTEXT_PROVIDER_H_
 
 #include "base/synchronization/lock.h"
 #include "cc/output/context_provider.h"
 #include "cc/test/test_gpu_memory_buffer_manager.h"
@@ skipping 18 matching lines @@
   TestInProcessContextProvider();
 
   bool BindToCurrentThread() override;
   gpu::gles2::GLES2Interface* ContextGL() override;
   gpu::ContextSupport* ContextSupport() override;
   class GrContext* GrContext() override;
   void InvalidateGrContext(uint32_t state) override;
   void SetupLock() override;
   base::Lock* GetLock() override;
   Capabilities ContextCapabilities() override;
-  bool IsContextLost() override;
   void VerifyContexts() override;
   void DeleteCachedResources() override;
   bool DestroyedOnMainThread() override;
   void SetLostContextCallback(
       const LostContextCallback& lost_context_callback) override;
   void SetMemoryPolicyChangedCallback(
       const MemoryPolicyChangedCallback& memory_policy_changed_callback)
       override;
 
  protected:
   friend class base::RefCountedThreadSafe<TestInProcessContextProvider>;
   ~TestInProcessContextProvider() override;
 
  private:
   TestGpuMemoryBufferManager gpu_memory_buffer_manager_;
   TestImageFactory image_factory_;
   scoped_ptr<gpu::GLInProcessContext> context_;
   skia::RefPtr<class GrContext> gr_context_;
   base::Lock context_lock_;
 };
 
 }  // namespace cc
 
 #endif  // CC_TEST_TEST_IN_PROCESS_CONTEXT_PROVIDER_H_