Tag TransportDIBs with the device scale factor they expect.

content/browser/renderer_host/backing_store_skia.cc

 // Copyright (c) 2012 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/browser/renderer_host/backing_store_skia.h"
 
 #include "content/browser/renderer_host/dip_util.h"
 #include "content/browser/renderer_host/render_process_host_impl.h"
 #include "content/public/browser/render_widget_host.h"
 #include "skia/ext/platform_canvas.h"
@@ skipping 33 matching lines @@
   // NOTE: The computation may be different when the canvas is a subrectangle of
   // a larger bitmap.
   return size().Scale(device_scale_factor_).GetArea() * 4;
 }
 
 void BackingStoreSkia::PaintToBackingStore(
     content::RenderProcessHost* process,
     TransportDIB::Id bitmap,
     const gfx::Rect& bitmap_rect,
     const std::vector<gfx::Rect>& copy_rects,
+    float scale_factor,
     const base::Closure& completion_callback,
     bool* scheduled_completion_callback) {
   *scheduled_completion_callback = false;
   if (bitmap_rect.IsEmpty())
     return;
 
   gfx::Rect pixel_rect = bitmap_rect.Scale(device_scale_factor_);
 
   const int width = pixel_rect.width();
   const int height = pixel_rect.height();
@@ skipping 48 matching lines @@
     return false;
 
   SkBitmap bitmap = skia::GetTopDevice(*output)->accessBitmap(true);
   SkIRect skrect = SkIRect::MakeXYWH(rect.x(), rect.y(), width, height);
   SkBitmap b;
   if (!canvas_->readPixels(skrect, &b))
     return false;
   output->writePixels(b, rect.x(), rect.y());
   return true;
 }