Index: cc/scheduler/begin_frame_source.h |
diff --git a/cc/scheduler/begin_frame_source.h b/cc/scheduler/begin_frame_source.h |
index 3b4e5231d183c90e3d666316123220dcfa956cdb..1e1938ba40f3967d652d3b3625950d6fb11d4a73 100644 |
--- a/cc/scheduler/begin_frame_source.h |
+++ b/cc/scheduler/begin_frame_source.h |
@@ -119,6 +119,12 @@ class CC_EXPORT BeginFrameSource { |
// (rather than toggling SetNeedsBeginFrames every frame). For example, the |
// BackToBackFrameSource uses them to make sure only one frame is pending at a |
// time. |
+ // |
+ // Note that the BeginFrameSource should not assume that the |ack| references |
+ // a valid BeginFrame sent by the source. The |ack| may reference a BeginFrame |
+ // sent by a different BeginFrameSource, and a malicious client may reference |
+ // any invalid frame. The source is responsible for checking for |
+ // validity/relevance of the BeginFrame itself. |
// TODO(eseckler): Use BeginFrameAcks in DisplayScheduler as described above. |
virtual void DidFinishFrame(BeginFrameObserver* obs, |
const BeginFrameAck& ack) = 0; |