LayerTreeHostImpl knows if it has an output surface.

cc/output/renderer.h

 // Copyright 2012 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_RENDERER_H_
 #define CC_OUTPUT_RENDERER_H_
 
 #include "base/basictypes.h"
 #include "cc/base/cc_export.h"
 #include "cc/quads/render_pass.h"
@@ skipping 55 matching lines @@
 
   // Waits for rendering to finish.
   virtual void Finish() = 0;
 
   virtual void DoNoOp() {}
 
   // Puts backbuffer onscreen.
   virtual void SwapBuffers(const CompositorFrameMetadata& metadata) = 0;
   virtual void ReceiveSwapBuffersAck(const CompositorFrameAck& ack) {}
 
-  virtual bool IsContextLost();
-
   bool visible() const { return visible_; }
   void SetVisible(bool visible);
 
  protected:
   explicit Renderer(RendererClient* client, const LayerTreeSettings* settings)
       : client_(client), settings_(settings), visible_(true) {}
 
   virtual void DidChangeVisibility() = 0;
 
   RendererClient* client_;
   const LayerTreeSettings* settings_;
   bool visible_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(Renderer);
 };
 
 }  // namespace cc
 
 #endif  // CC_OUTPUT_RENDERER_H_