Remove ContextProvider::IsContextLost.

cc/output/context_provider.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 CC_OUTPUT_CONTEXT_PROVIDER_H_
 #define CC_OUTPUT_CONTEXT_PROVIDER_H_
 
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "cc/base/cc_export.h"
@@ skipping 40 matching lines @@
   // Sets up a lock so this context can be used from multiple threads.
   virtual void SetupLock() = 0;
 
   // Returns the lock that should be held if using this context from multiple
   // threads.
   virtual base::Lock* GetLock() = 0;
 
   // Returns the capabilities of the currently bound 3d context.
   virtual Capabilities ContextCapabilities() = 0;
 
-  // Checks if the context is currently known to be lost.
-  virtual bool IsContextLost() = 0;
-
   // Ask the provider to check if the contexts are valid or lost. If they are,
   // this should invalidate the provider so that it can be replaced with a new
   // one.
   virtual void VerifyContexts() = 0;
 
   // Delete all cached gpu resources.
   virtual void DeleteCachedResources() = 0;
 
   // A method to be called from the main thread that should return true if
   // the context inside the provider is no longer valid.
@@ skipping 15 matching lines @@
       const MemoryPolicyChangedCallback& memory_policy_changed_callback) = 0;
 
  protected:
   friend class base::RefCountedThreadSafe<ContextProvider>;
   virtual ~ContextProvider() {}
 };
 
 }  // namespace cc
 
 #endif  // CC_OUTPUT_CONTEXT_PROVIDER_H_