Remove ContextProvider::IsContextLost.

cc/test/test_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_CONTEXT_PROVIDER_H_
 #define CC_TEST_TEST_CONTEXT_PROVIDER_H_
 
 #include "base/callback.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
@@ skipping 19 matching lines @@
 
   bool BindToCurrentThread() override;
   void DetachFromThread() override;
   Capabilities ContextCapabilities() 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;
-  bool IsContextLost() override;
   void VerifyContexts() override;
   void DeleteCachedResources() override;
   bool DestroyedOnMainThread() override;
   void SetLostContextCallback(const LostContextCallback& cb) override;
   void SetMemoryPolicyChangedCallback(
       const MemoryPolicyChangedCallback& cb) override;
 
   TestWebGraphicsContext3D* TestContext3d();
 
   // This returns the TestWebGraphicsContext3D but is valid to call
@@ skipping 35 matching lines @@
 
   base::WeakPtrFactory<TestContextProvider> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(TestContextProvider);
 };
 
 }  // namespace cc
 
 #endif  // CC_TEST_TEST_CONTEXT_PROVIDER_H_