sync compositor: pass simple gfx types by const ref

content/public/browser/android/synchronous_compositor.h

 // 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.
 
 #ifndef CONTENT_PUBLIC_BROWSER_ANDROID_SYNCHRONOUS_COMPOSITOR_H_
 #define CONTENT_PUBLIC_BROWSER_ANDROID_SYNCHRONOUS_COMPOSITOR_H_
 
 #include "base/memory/ref_counted.h"
 #include "content/common/content_export.h"
 #include "gpu/command_buffer/service/in_process_command_buffer.h"
@@ skipping 30 matching lines @@
   // instance as needed, but only if |client| is non-nullptr.
   static void SetClientForWebContents(WebContents* contents,
                                       SynchronousCompositorClient* client);
 
   static void SetGpuService(
       scoped_refptr<gpu::InProcessCommandBuffer::Service> service);
 
   // "On demand" hardware draw. The content is first clipped to |damage_area|,
   // then transformed through |transform|, and finally clipped to |view_size|.
   virtual scoped_ptr<cc::CompositorFrame> DemandDrawHw(
-      gfx::Size surface_size,
+      const gfx::Size& surface_size,
       const gfx::Transform& transform,
-      gfx::Rect viewport,
-      gfx::Rect clip,
-      gfx::Rect viewport_rect_for_tile_priority,
+      const gfx::Rect& viewport,
+      const gfx::Rect& clip,
+      const gfx::Rect& viewport_rect_for_tile_priority,
       const gfx::Transform& transform_for_tile_priority) = 0;
 
   // For delegated rendering, return resources from parent compositor to this.
   // Note that all resources must be returned before ReleaseHwDraw.
   virtual void ReturnResources(const cc::CompositorFrameAck& frame_ack) = 0;
 
   // "On demand" SW draw, into the supplied canvas (observing the transform
   // and clip set there-in).
   virtual bool DemandDrawSw(SkCanvas* canvas) = 0;
 
@@ skipping 14 matching lines @@
   // and if any input animation is active, it should tick now.
   virtual void OnComputeScroll(base::TimeTicks animation_time) = 0;
 
  protected:
   virtual ~SynchronousCompositor() {}
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_ANDROID_SYNCHRONOUS_COMPOSITOR_H_