Pass the device scale factor in the command line to renderer processes.

ui/base/resource/resource_bundle.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 "ui/base/resource/resource_bundle.h"
 
 #include <limits>
 #include <vector>
 
 #include "base/big_endian.h"
@@ skipping 587 matching lines @@
       default_to_100P = false;
     }
   }
   if (default_to_100P)
     supported_scale_factors.push_back(SCALE_FACTOR_100P);
 #endif
   ui::SetSupportedScaleFactors(supported_scale_factors);
 #if defined(OS_WIN)
   // Must be called _after_ supported scale factors are set since it
   // uses them.
-  ui::win::InitDeviceScaleFactor();
+  // Don't initialize the device scale factor if it has already been
+  // initialized.
+  if (!gfx::win::IsDeviceScaleFactorSet())
+    ui::win::InitDeviceScaleFactor();
 #endif
 }
 
 void ResourceBundle::FreeImages() {
   images_.clear();
 }
 
 void ResourceBundle::AddDataPackFromPathInternal(const base::FilePath& path,
                                                  ScaleFactor scale_factor,
                                                  bool optional) {
@@ skipping 197 matching lines @@
 // static
 bool ResourceBundle::DecodePNG(const unsigned char* buf,
                                size_t size,
                                SkBitmap* bitmap,
                                bool* fell_back_to_1x) {
   *fell_back_to_1x = PNGContainsFallbackMarker(buf, size);
   return gfx::PNGCodec::Decode(buf, size, bitmap);
 }
 
 }  // namespace ui