Make delegated software renderer work on Mac

cc/output/output_surface.cc

Index: cc/output/output_surface.cc
diff --git a/cc/output/output_surface.cc b/cc/output/output_surface.cc
index 0f68b5b048d749842289dd6aac531dad516bbeda..80def54b805ac67e507f4a7ff2c606e0dbddd9a3 100644
--- a/cc/output/output_surface.cc
+++ b/cc/output/output_surface.cc
@@ -226,7 +226,7 @@ void OutputSurface::Reshape(const gfx::Size& size, float scale_factor) {
         size.width(), size.height(), scale_factor);
   }
   if (software_device_)
-    software_device_->Resize(size);
+    software_device_->Resize(size, scale_factor);
 }
 
 gfx::Size OutputSurface::SurfaceSize() const {