sync compositor: Set display viewport for software draw

cc/surfaces/display.h

 // Copyright 2014 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_SURFACES_DISPLAY_H_
 #define CC_SURFACES_DISPLAY_H_
 
 #include <memory>
 #include <vector>
 
@@ skipping 58 matching lines @@
   void Initialize(DisplayClient* client,
                   SurfaceManager* surface_manager,
                   uint32_t compositor_surface_namespace);
 
   // device_scale_factor is used to communicate to the external window system
   // what scale this was rendered at.
   void SetSurfaceId(const SurfaceId& id, float device_scale_factor);
   void Resize(const gfx::Size& new_size);
   void SetColorSpace(const gfx::ColorSpace& color_space);
   void SetExternalClip(const gfx::Rect& clip);
+  void SetExternalViewport(const gfx::Rect& viewport);
   void SetOutputIsSecure(bool secure);
 
   const SurfaceId& CurrentSurfaceId();
 
   // DisplaySchedulerClient implementation.
   bool DrawAndSwap() override;
 
   // OutputSurfaceClient implementation.
   void CommitVSyncParameters(base::TimeTicks timebase,
                              base::TimeDelta interval) override;
@@ skipping 37 matching lines @@
 
   DisplayClient* client_;
   SurfaceManager* surface_manager_;
   uint32_t compositor_surface_namespace_;
   SurfaceId current_surface_id_;
   gfx::Size current_surface_size_;
   float device_scale_factor_ = 1.f;
   gfx::ColorSpace device_color_space_;
   bool swapped_since_resize_ = false;
   gfx::Rect external_clip_;
+  gfx::Rect external_viewport_;
   gfx::Size enlarge_texture_amount_;
   bool output_is_secure_ = false;
 
   // The begin_frame_source_ is often known by the output_surface_ and
   // the scheduler_.
   std::unique_ptr<BeginFrameSource> begin_frame_source_;
   std::unique_ptr<OutputSurface> output_surface_;
   std::unique_ptr<DisplayScheduler> scheduler_;
   std::unique_ptr<ResourceProvider> resource_provider_;
   std::unique_ptr<SurfaceAggregator> aggregator_;
   std::unique_ptr<TextureMailboxDeleter> texture_mailbox_deleter_;
   std::unique_ptr<DirectRenderer> renderer_;
   SoftwareRenderer* software_renderer_ = nullptr;
   std::vector<ui::LatencyInfo> stored_latency_info_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(Display);
 };
 
 }  // namespace cc
 
 #endif  // CC_SURFACES_DISPLAY_H_