Implement HiDPI support in Pepper dev interface

ppapi/thunk/ppb_graphics_2d_thunk.cc

Index: ppapi/thunk/ppb_graphics_2d_thunk.cc
diff --git a/ppapi/thunk/ppb_graphics_2d_thunk.cc b/ppapi/thunk/ppb_graphics_2d_thunk.cc
index 393b4c663d63bcde44c287a98be4cd89658ca7fe..52bfe18caedb0f90493247d32a3dba9ea71f3604 100644
--- a/ppapi/thunk/ppb_graphics_2d_thunk.cc
+++ b/ppapi/thunk/ppb_graphics_2d_thunk.cc
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "ppapi/c/dev/ppb_graphics_2d_dev.h"
 #include "ppapi/c/pp_completion_callback.h"
 #include "ppapi/c/pp_errors.h"
 #include "ppapi/c/ppb_graphics_2d.h"
@@ -78,6 +79,20 @@ int32_t Flush(PP_Resource graphics_2d,
   return enter.SetResult(enter.object()->Flush(callback));
 }
 
+PP_Bool SetScale(PP_Resource graphics_2d, float scale) {
+  EnterGraphics2D enter(graphics_2d, true);
+  if (enter.failed())
+    return PP_FALSE;
+  return PP_FromBool(enter.object()->SetScale(scale));
+}
+
+float GetScale(PP_Resource graphics_2d) {
+  EnterGraphics2D enter(graphics_2d, true);
+  if (enter.failed())
+    return 0.0f;
+  return enter.object()->GetScale();
+}
+
 const PPB_Graphics2D g_ppb_graphics_2d_thunk = {
   &Create,
   &IsGraphics2D,
@@ -88,11 +103,20 @@ const PPB_Graphics2D g_ppb_graphics_2d_thunk = {
   &Flush
 };
 
+const PPB_Graphics2D_Dev g_ppb_graphics_2d_dev_thunk = {
+  &SetScale,
+  &GetScale
+};
+
 }  // namespace
 
 const PPB_Graphics2D_1_0* GetPPB_Graphics2D_1_0_Thunk() {
   return &g_ppb_graphics_2d_thunk;
 }
 
+const PPB_Graphics2D_Dev_0_1* GetPPB_Graphics2D_Dev_0_1_Thunk() {
+  return &g_ppb_graphics_2d_dev_thunk;
+}
+
 }  // namespace thunk
 }  // namespace ppapi