Changing animate to beginFrame and use struct rather than naked double to allow extension.

public/web/WebWidget.h

Index: public/web/WebWidget.h
diff --git a/public/web/WebWidget.h b/public/web/WebWidget.h
index 54b00f3506d41f3f114ebfb022abf5ac6b577916..d0e12437890840de7d3f096cb11941719c0c1f65 100644
--- a/public/web/WebWidget.h
+++ b/public/web/WebWidget.h
@@ -35,6 +35,7 @@
 #include "../platform/WebCommon.h"
 #include "../platform/WebRect.h"
 #include "../platform/WebSize.h"
+#include "WebBeginFrameArgs.h"
 #include "WebCompositionUnderline.h"
 #include "WebTextDirection.h"
 #include "WebTextInputInfo.h"
@@ -88,7 +89,12 @@ public:
 
     // Called to update imperative animation state. This should be called before
     // paint, although the client can rate-limit these calls.
-    virtual void animate(double monotonicFrameBeginTime) { }
+    // FIXME: Remove this function once Chrome side patch lands.
+    void animate(double monotonicFrameBeginTime)
+    {
+        beginFrame(WebBeginFrameArgs(monotonicFrameBeginTime));
+    }
+    virtual void beginFrame(const WebBeginFrameArgs& frameTime) { }
 
     // Called to layout the WebWidget. This MUST be called before Paint,
     // and it may result in calls to WebWidgetClient::didInvalidateRect.