Setting a custom background on a HiDPI display will result in the background only being applied to …

content/renderer/render_widget.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/renderer/render_widget.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
@@ skipping 756 matching lines @@
                                      SkShader::kRepeat_TileMode,
                                      SkShader::kRepeat_TileMode));
     paint.setShader(shader.get());
 
     // Use kSrc_Mode to handle background_ transparency properly.
     paint.setXfermodeMode(SkXfermode::kSrc_Mode);
 
     // Canvas could contain multiple update rects. Clip to given rect so that
     // we don't accidentally clear other update rects.
     canvas->save();
+    canvas->scale(device_scale_factor_, device_scale_factor_);
     canvas->clipRect(gfx::RectToSkRect(rect));
     canvas->drawPaint(paint);
     canvas->restore();
   }
 
   // First see if this rect is a plugin that can paint itself faster.
   TransportDIB* optimized_dib = NULL;
   gfx::Rect optimized_copy_rect, optimized_copy_location;
   float dib_scale_factor;
   webkit::ppapi::PluginInstance* optimized_instance =
@@ skipping 1349 matching lines @@
 bool RenderWidget::WillHandleGestureEvent(
     const WebKit::WebGestureEvent& event) {
   return false;
 }
 
 bool RenderWidget::HasTouchEventHandlersAt(const gfx::Point& point) const {
   return true;
 }
 
 }  // namespace content