Adds a didReceiveInputEvent api to the blink scheduler

Source/platform/scheduler/Scheduler.cpp

Index: Source/platform/scheduler/Scheduler.cpp
diff --git a/Source/platform/scheduler/Scheduler.cpp b/Source/platform/scheduler/Scheduler.cpp
index a49b9af7eeb10d0f3f8b9745491d9e611ae86a7e..4257b8bcc3a84c4bf8414c1be3d089b608a6ceaf 100644
--- a/Source/platform/scheduler/Scheduler.cpp
+++ b/Source/platform/scheduler/Scheduler.cpp
@@ -162,6 +162,12 @@ void Scheduler::postInputTask(const TraceLocation& location, const Task& task)
     TRACE_COUNTER1(TRACE_DISABLED_BY_DEFAULT("blink.scheduler"), "PendingHighPriorityTasks", m_highPriorityTaskCount);
 }
 
+void Scheduler::didReceiveInputEvent()

[eseidel, 2014/09/10 16:10:34]

How often is this called?

[alexclarke, 2014/09/11 15:21:12]

At most a handful of times per frame.

+{
+    Locker<Mutex> lock(m_pendingTasksMutex);
+    setLatencyMode(LowLatency);
+}
+
 void Scheduler::postCompositorTask(const TraceLocation& location, const Task& task)
 {
     Locker<Mutex> lock(m_pendingTasksMutex);