Make delegated software renderer work on Mac

content/browser/compositor/software_output_device_win.cc

Index: content/browser/compositor/software_output_device_win.cc
diff --git a/content/browser/compositor/software_output_device_win.cc b/content/browser/compositor/software_output_device_win.cc
index 3c938bf325ae2eac4bdfd032bfdd27b5b625b50e..60d52887e4a55f94a3f73c2517e8eb495b613902 100644
--- a/content/browser/compositor/software_output_device_win.cc
+++ b/content/browser/compositor/software_output_device_win.cc
@@ -29,14 +29,17 @@ SoftwareOutputDeviceWin::~SoftwareOutputDeviceWin() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 }
 
-void SoftwareOutputDeviceWin::Resize(const gfx::Size& viewport_size) {
+void SoftwareOutputDeviceWin::Resize(const gfx::Size& viewport_pixel_size,
+                                     float scale_factor) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
-  if (viewport_size_ == viewport_size)
+  scale_factor_ = scale_factor;
+
+  if (viewport_size_ == viewport_pixel_size)
     return;
 
-  viewport_size_ = viewport_size;
-  contents_.reset(new gfx::Canvas(viewport_size, 1.0f, true));
+  viewport_size_ = viewport_pixel_size;
+  contents_.reset(new gfx::Canvas(viewport_pixel_size, 1.0f, true));
   memset(&bitmap_info_, 0, sizeof(bitmap_info_));
   gfx::CreateBitmapHeader(viewport_size_.width(), viewport_size_.height(),
                           &bitmap_info_.bmiHeader);