blimp: Cleanup class/struct forward declarations

blimp/client/support/compositor/blimp_layer_tree_settings.h

 // Copyright 2015 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 BLIMP_CLIENT_SUPPORT_COMPOSITOR_BLIMP_LAYER_TREE_SETTINGS_H_
 #define BLIMP_CLIENT_SUPPORT_COMPOSITOR_BLIMP_LAYER_TREE_SETTINGS_H_
 
-namespace base {
-class CommandLine;
-}
-
 namespace cc {
 class LayerTreeSettings;
 }
 
-namespace gfx {
-class Size;
-}
-
 namespace blimp {
 namespace client {
 
 // Populates client |settings| based on defaults & command line flags.  This
 // might have to be tweaked into a message protocol if it turns out
 // the host compositor needs to actually drive some specific settings of the
 // client.
 void PopulateCommonLayerTreeSettings(cc::LayerTreeSettings* settings);
 
 }  // namespace client
 }  // namespace blimp
 
 #endif  // BLIMP_CLIENT_SUPPORT_COMPOSITOR_BLIMP_LAYER_TREE_SETTINGS_H_