Remove ContextProvider::IsContextLost.

content/renderer/gpu/mailbox_output_surface.cc

 // Copyright (c) 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.
 
 #include "content/renderer/gpu/mailbox_output_surface.h"
 
 #include "base/logging.h"
 #include "cc/output/compositor_frame.h"
 #include "cc/output/compositor_frame_ack.h"
 #include "cc/output/gl_frame_data.h"
@@ skipping 181 matching lines @@
     pending_textures_.pop_front();
   }
   CompositorOutputSurface::OnSwapAck(output_surface_id, ack);
 }
 
 void MailboxOutputSurface::SwapBuffers(cc::CompositorFrame* frame) {
   DCHECK(frame->gl_frame_data);
   DCHECK(!surface_size_.IsEmpty());
   DCHECK(surface_size_ == current_backing_.size);
   DCHECK(frame->gl_frame_data->size == current_backing_.size);
-  DCHECK(!current_backing_.mailbox.IsZero() ||
-         context_provider_->IsContextLost());
+  DCHECK_IMPLIES(current_backing_.mailbox.IsZero(),
+                 context_provider_->ContextGL()->GetGraphicsResetStatusKHR() !=
+                     GL_NO_ERROR);
 
   frame->gl_frame_data->mailbox = current_backing_.mailbox;
   context_provider_->ContextGL()->Flush();
   frame->gl_frame_data->sync_point =
       context_provider_->ContextGL()->InsertSyncPointCHROMIUM();
   CompositorOutputSurface::SwapBuffers(frame);
 
   pending_textures_.push_back(current_backing_);
   current_backing_ = TransferableFrame();
 }
 
 size_t MailboxOutputSurface::GetNumAcksPending() {
   DCHECK(pending_textures_.size());
   return pending_textures_.size() - 1;
 }
 
 }  // namespace content