Compute the popup location/size correctly when use-zoom-for-dsf is enabled.

third_party/WebKit/public/web/WebWidgetClient.h

Index: third_party/WebKit/public/web/WebWidgetClient.h
diff --git a/third_party/WebKit/public/web/WebWidgetClient.h b/third_party/WebKit/public/web/WebWidgetClient.h
index 41fe6692ea5aac06cdf84e4e3614cece960bdede..175cbacbb1f56d9c20693b5e1dead78ce56f653f 100644
--- a/third_party/WebKit/public/web/WebWidgetClient.h
+++ b/third_party/WebKit/public/web/WebWidgetClient.h
@@ -175,6 +175,10 @@ public:
     // press or gesture tap.
     // Note: This is called even when the mouse down event is prevent default.
     virtual void onMouseDown(const WebNode& mouseDownNode) { }
+
+    // Converts the WebRect from viewport coordinates to screen coordinates.
+    virtual void convertViewportToScreen(WebRect* rect) {}
+
 protected:
     ~WebWidgetClient() { }
 };