Add pixel readback to page popup

public/web/WebWidget.h

Index: public/web/WebWidget.h
diff --git a/public/web/WebWidget.h b/public/web/WebWidget.h
index 149e98356e253b38acd64e09c1e2971084011947..5a7a80234b8aa97843930d54bc3711b4ab65a968 100644
--- a/public/web/WebWidget.h
+++ b/public/web/WebWidget.h
@@ -33,6 +33,7 @@
 
 #include "../platform/WebCanvas.h"
 #include "../platform/WebCommon.h"
+#include "../platform/WebPoint.h"
 #include "../platform/WebRect.h"
 #include "../platform/WebSize.h"
 #include "WebBeginFrameArgs.h"
@@ -46,7 +47,9 @@ class WebCompositeAndReadbackAsyncCallback;
 class WebInputEvent;
 class WebLayerTreeView;
 class WebMouseEvent;
+class WebPagePopup;
 class WebString;
+class WebWidgetClient;
 struct WebPoint;
 struct WebRenderingStats;
 template <typename T> class WebVector;
@@ -255,6 +258,10 @@ public:
     // content.
     virtual WebColor backgroundColor() const { return 0xFFFFFFFF; /* SK_ColorWHITE */ }
 
+    // The currently open page popup, which are calendar and datalist pickers
+    // but not the select popup.
+    virtual WebPagePopup* pagePopup() const { return 0; }
+
 protected:
     ~WebWidget() { }
 };