Apply viewport to dip scale to Graphics2D, Compositor

content/renderer/pepper/pepper_compositor_host.h

Index: content/renderer/pepper/pepper_compositor_host.h
diff --git a/content/renderer/pepper/pepper_compositor_host.h b/content/renderer/pepper/pepper_compositor_host.h
index 9168e7d11138d4ee96c73d36177c3acf2ca8be32..0163a74f80ea089aa365bd8357842154487d6ad2 100644
--- a/content/renderer/pepper/pepper_compositor_host.h
+++ b/content/renderer/pepper/pepper_compositor_host.h
@@ -51,6 +51,11 @@ class PepperCompositorHost : public ppapi::host::ResourceHost {
 
   void ViewInitiatedPaint();
 
+  void set_viewport_to_dip_scale(float viewport_to_dip_scale) {
+    DCHECK_LT(0, viewport_to_dip_scale_);
+    viewport_to_dip_scale_ = viewport_to_dip_scale;
+  }
+
  private:
   void ImageReleased(int32_t id,
                      std::unique_ptr<base::SharedMemory> shared_memory,
@@ -102,6 +107,10 @@ class PepperCompositorHost : public ppapi::host::ResourceHost {
 
   ppapi::host::ReplyMessageContext commit_layers_reply_context_;
 
+  // The scale between the viewport and dip. This differs in
+  // use-zoom-for-dsf mode where the content is scaled by zooming.
+  float viewport_to_dip_scale_ = 1.0f;
+
   base::WeakPtrFactory<PepperCompositorHost> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PepperCompositorHost);