Support device scale factor test with popups in LayoutTest

content/shell/renderer/layout_test/blink_test_runner.h

Index: content/shell/renderer/layout_test/blink_test_runner.h
diff --git a/content/shell/renderer/layout_test/blink_test_runner.h b/content/shell/renderer/layout_test/blink_test_runner.h
index 9e0f0534bcc861a6246cc51cde9b9579d845dd3d..b5369dc5654ae6a4752bf1562721f1e3fa3d374f 100644
--- a/content/shell/renderer/layout_test/blink_test_runner.h
+++ b/content/shell/renderer/layout_test/blink_test_runner.h
@@ -149,6 +149,8 @@ class BlinkTestRunner : public RenderViewObserver,
     blink::WebLocalFrame* frame,
     const blink::WebPluginParams& params) override;
   void OnWebTestProxyBaseDestroy(test_runner::WebTestProxyBase* proxy) override;
+  blink::WebPoint ConvertDIPToNative(
+      const blink::WebPoint& point_in_dip) const override;
 
   void Reset();
 
@@ -198,6 +200,8 @@ class BlinkTestRunner : public RenderViewObserver,
   scoped_ptr<LeakDetector> leak_detector_;
   bool needs_leak_detector_;
 
+  float device_scale_factor_;
+
   DISALLOW_COPY_AND_ASSIGN(BlinkTestRunner);
 };