Remove offscreen compositor contexts.

cc/test/layer_tree_pixel_test.cc

 // 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.
 
 #include "cc/test/layer_tree_pixel_test.h"
 
 #include "base/command_line.h"
 #include "base/path_service.h"
 #include "cc/base/switches.h"
 #include "cc/layers/solid_color_layer.h"
@@ skipping 46 matching lines @@
       output_surface = make_scoped_ptr(
           new PixelTestOutputSurface(new TestInProcessContextProvider));
       break;
     }
   }
 
   output_surface->set_surface_expansion_size(surface_expansion_size);
   return output_surface.PassAs<OutputSurface>();
 }
 
-scoped_refptr<ContextProvider> LayerTreePixelTest::OffscreenContextProvider() {
-  return scoped_refptr<ContextProvider>(new TestInProcessContextProvider);
-}
-
 void LayerTreePixelTest::CommitCompleteOnThread(LayerTreeHostImpl* impl) {
   LayerTreeImpl* commit_tree =
       impl->pending_tree() ? impl->pending_tree() : impl->active_tree();
   if (commit_tree->source_frame_number() != 0)
     return;
 
   gfx::Rect viewport = impl->DeviceViewport();
   // The viewport has a 0,0 origin without external influence.
   EXPECT_EQ(gfx::Point().ToString(), viewport.origin().ToString());
   // Be that influence!
@@ skipping 281 matching lines @@
 
   *texture_mailbox = TextureMailbox(mailbox, GL_TEXTURE_2D, sync_point);
   *release_callback = SingleReleaseCallback::Create(
       base::Bind(&LayerTreePixelTest::ReleaseTextureMailbox,
                  base::Unretained(this),
                  base::Passed(&context),
                  texture_id));
 }
 
 }  // namespace cc