SurfaceFlinger: some bug fixes on Scheduler

 - use mHWVsyncAvailable from Scheduler instead of SF
 - call DispSync::dump() on Scheduler
 - Revert VSYNC-app and VSYNC-sf names as systrace expects these
   names for vsync events

Test: run some applications
Change-Id: Ida0ba67eee55471d1df7f5e89a7b2ad36ab7074d
diff --git a/services/surfaceflinger/Scheduler/Scheduler.cpp b/services/surfaceflinger/Scheduler/Scheduler.cpp
index 7fd7762..af439f7 100644
--- a/services/surfaceflinger/Scheduler/Scheduler.cpp
+++ b/services/surfaceflinger/Scheduler/Scheduler.cpp
@@ -190,9 +190,15 @@
 }
 
 void Scheduler::setVsyncPeriod(const nsecs_t period) {
+    std::lock_guard<std::mutex> lock(mHWVsyncLock);
     mPrimaryDispSync->reset();
     mPrimaryDispSync->setPeriod(period);
-    enableHardwareVsync();
+
+    if (!mPrimaryHWVsyncEnabled) {
+        mPrimaryDispSync->beginResync();
+        mEventControlThread->setVsyncEnabled(true);
+        mPrimaryHWVsyncEnabled = true;
+    }
 }
 
 void Scheduler::addResyncSample(const nsecs_t timestamp) {
@@ -228,10 +234,19 @@
     mHWVsyncAvailable = makeAvailable;
 }
 
+bool Scheduler::getHWSyncAvailable() {
+    std::lock_guard<std::mutex> lock(mHWVsyncLock);
+    return mHWVsyncAvailable;
+}
+
 nsecs_t Scheduler::expectedPresentTime() {
     return mPrimaryDispSync->expectedPresentTime();
 }
 
+void Scheduler::dumpPrimaryDispSync(std::string& result) const {
+    mPrimaryDispSync->dump(result);
+}
+
 void Scheduler::addFramePresentTimeForLayer(const nsecs_t framePresentTime, bool isAutoTimestamp,
                                             const std::string layerName) {
     // This is V1 logic. It calculates the average FPS based on the timestamp frequency