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

public/platform/WebFrameTime.h

Index: public/platform/WebFrameTime.h
diff --git a/public/platform/WebWaitableEvent.h b/public/platform/WebFrameTime.h
similarity index 58%
copy from public/platform/WebWaitableEvent.h
copy to public/platform/WebFrameTime.h
index f1b59f0a263afe5afd887863e98d52d9cfa3e95e..1050291c23f3db6177e84cc5bb3a7aa9feec7b15 100644
--- a/public/platform/WebWaitableEvent.h
+++ b/public/platform/WebFrameTime.h
@@ -28,28 +28,42 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef WebWaitableEvent_h
-#define WebWaitableEvent_h
+#ifndef WebFrameTime_h
+#define WebFrameTime_h
 
 #include "WebCommon.h"
 
 namespace blink {
 
-// Provides a thread synchronization that can be used to allow one thread to
-// wait until another thread to finish some work.
-class WebWaitableEvent {
-public:
-    virtual ~WebWaitableEvent() { }
+struct WebFrameTime {
+    WebFrameTime(double lastFrameTime, double renderDeadline, double displayFrameTime, double predictedNextDisplayFrameTime)
+        : lastFrameTime(lastFrameTime)
+        , renderDeadline(renderDeadline)
+        , displayFrameTime(displayFrameTime)
+        , predictedNextDisplayFrameTime(predictedNextDisplayFrameTime)
+    { }
 
-    // Waits indefinitely for the event to be signaled.
-    virtual void wait() = 0;
+    // FIXME(mithro): Upgrade the time in CLOCK_MONOTONIC values to use a
+    // TimeTick like class rather than a bare double.
 
-    // Puts the event in the signaled state. Causing any thread blocked on Wait
-    // to be woken up. The event state is reset to non-signaled after
-    // a waiting thread has been released.
-    virtual void signal() = 0;
+    // Time in CLOCK_MONOTONIC that is the most recent vsync time.
+    double lastFrameTime;
+
+    // Time in CLOCK_MONOTONIC by which rendering must be finished by to not
+    // stall the pipeline.
+    double renderDeadline;
+
+    // Time in CLOCK_MONOTONIC that the frame will hit the glass of the display
+    // if rendered within the deadline. This time may be identical to
+    // lastFrameTime.
+    double displayFrameTime;
+
+    // Time in CLOCK_MONOTONIC that is the predicated next value for
+    // displayFrameTime. The next displayFrameTime should be this value or
+    // greater.
+    double predictedNextDisplayFrameTime;
 };
 
 } // namespace blink
 
-#endif // WebWaitableEvent_h
+#endif