Cache frame event history producer-side.

* Producer maintains a recent history of frames.
* Producer only does a binder call if requested
    informatiVon doesn't exist in the cache.
* Consumer sends fences to the producer, which
    can be queried for timestamps without a
    binder call.

Test: adb shell /data/nativetest/libgui_test/libgui_test
--gtest_filter=*GetFrameTimestamps*

Change-Id: I8a64579407cc2935f5c659462cb227b07ba27e43
diff --git a/include/gui/IGraphicBufferProducer.h b/include/gui/IGraphicBufferProducer.h
index 493143a..612a902 100644
--- a/include/gui/IGraphicBufferProducer.h
+++ b/include/gui/IGraphicBufferProducer.h
@@ -588,13 +588,8 @@
     virtual status_t getLastQueuedBuffer(sp<GraphicBuffer>* outBuffer,
             sp<Fence>* outFence, float outTransformMatrix[16]) = 0;
 
-    // Attempts to retrieve timestamp information for the given frame number.
-    // If information for the given frame number is not found, returns false.
-    // Returns true otherwise.
-    //
-    // If a fence has not yet signaled the timestamp returned will be 0;
-    virtual bool getFrameTimestamps(uint64_t /*frameNumber*/,
-            FrameTimestamps* /*outTimestamps*/) { return false; }
+    // Gets the frame events that haven't already been retrieved.
+    virtual void getFrameTimestamps(FrameEventHistoryDelta* /*outDelta*/) {}
 
     // Returns a unique id for this BufferQueue
     virtual status_t getUniqueId(uint64_t* outId) const = 0;