[#2] Pass gfx structs by const ref (gfx::Rect, gfx::RectF)

content/renderer/gpu/compositor_software_output_device.cc

 // Copyright (c) 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 "content/renderer/gpu/compositor_software_output_device.h"
 
 #include "base/logging.h"
 #include "cc/output/software_frame_data.h"
 #include "content/renderer/render_process.h"
 #include "third_party/skia/include/core/SkBitmapDevice.h"
@@ skipping 113 matching lines @@
       buffers_[i] = NULL;
     }
   }
   buffers_.clear();
   current_index_ = -1;
 }
 
 void CompositorSoftwareOutputDevice::EnsureBackbuffer() {
 }
 
-SkCanvas* CompositorSoftwareOutputDevice::BeginPaint(gfx::Rect damage_rect) {
+SkCanvas* CompositorSoftwareOutputDevice::BeginPaint(
+    const gfx::Rect& damage_rect) {
   DCHECK(CalledOnValidThread());
 
   Buffer* previous = NULL;
   if (current_index_ != size_t(-1))
     previous = buffers_[current_index_];
   current_index_ = FindFreeBuffer(current_index_ + 1);
   Buffer* current = buffers_[current_index_];
   DCHECK(current->free());
   current->SetFree(false);
 
@@ skipping 77 matching lines @@
     return;
   } else {
     it = std::find_if(awaiting_ack_.begin(), awaiting_ack_.end(),
                       CompareById(id));
     DCHECK(it != awaiting_ack_.end());
     awaiting_ack_.erase(it);
   }
 }
 
 }  // namespace content