Roll cc snapshot up to 127605

cc/CCFrameRateController.cpp

Index: cc/CCFrameRateController.cpp
diff --git a/cc/CCFrameRateController.cpp b/cc/CCFrameRateController.cpp
index b264bc27ebcd4259b0eb6af669f4dc0d214b5198..15ff94c03c03c2e42a3cd379080d68c83226ba2b 100644
--- a/cc/CCFrameRateController.cpp
+++ b/cc/CCFrameRateController.cpp
@@ -11,6 +11,14 @@
 #include "TraceEvent.h"
 #include <wtf/CurrentTime.h>
 
+namespace {
+
+// This will be the maximum number of pending frames unless
+// CCFrameRateController::setMaxFramesPending is called.
+const int defaultMaxFramesPending = 2;
+
+}
+
 namespace WebCore {
 
 class CCFrameRateControllerTimeSourceAdapter : public CCTimeSourceClient {
@@ -32,9 +40,10 @@ private:
 CCFrameRateController::CCFrameRateController(PassRefPtr<CCTimeSource> timer)
     : m_client(0)
     , m_numFramesPending(0)
-    , m_maxFramesPending(0)
+    , m_maxFramesPending(defaultMaxFramesPending)
     , m_timeSource(timer)
     , m_active(false)
+    , m_swapBuffersCompleteSupported(true)
     , m_isTimeSourceThrottling(true)
 {
     m_timeSourceClientAdapter = CCFrameRateControllerTimeSourceAdapter::create(this);
@@ -44,8 +53,9 @@ CCFrameRateController::CCFrameRateController(PassRefPtr<CCTimeSource> timer)
 CCFrameRateController::CCFrameRateController(CCThread* thread)
     : m_client(0)
     , m_numFramesPending(0)
-    , m_maxFramesPending(0)
+    , m_maxFramesPending(defaultMaxFramesPending)
     , m_active(false)
+    , m_swapBuffersCompleteSupported(true)
     , m_isTimeSourceThrottling(false)
 {
     m_manualTicker = adoptPtr(new CCTimer(thread, this));
@@ -76,6 +86,7 @@ void CCFrameRateController::setActive(bool active)
 
 void CCFrameRateController::setMaxFramesPending(int maxFramesPending)
 {
+    ASSERT(maxFramesPending > 0);
     m_maxFramesPending = maxFramesPending;
 }
 
@@ -85,12 +96,17 @@ void CCFrameRateController::setTimebaseAndInterval(double timebase, double inter
         m_timeSource->setTimebaseAndInterval(timebase, intervalSeconds);
 }
 
+void CCFrameRateController::setSwapBuffersCompleteSupported(bool supported)
+{
+    m_swapBuffersCompleteSupported = supported;
+}
+
 void CCFrameRateController::onTimerTick()
 {
     ASSERT(m_active);
 
     // Don't forward the tick if we have too many frames in flight.
-    if (m_maxFramesPending && m_numFramesPending >= m_maxFramesPending) {
+    if (m_numFramesPending >= m_maxFramesPending) {
         TRACE_EVENT0("cc", "CCFrameRateController::onTimerTickButMaxFramesPending");
         return;
     }
@@ -98,8 +114,7 @@ void CCFrameRateController::onTimerTick()
     if (m_client)
         m_client->vsyncTick();
 
-    if (!m_isTimeSourceThrottling
-        && (!m_maxFramesPending || m_numFramesPending < m_maxFramesPending))
+    if (m_swapBuffersCompleteSupported && !m_isTimeSourceThrottling && m_numFramesPending < m_maxFramesPending)
         postManualTick();
 }
 
@@ -116,11 +131,16 @@ void CCFrameRateController::onTimerFired()
 
 void CCFrameRateController::didBeginFrame()
 {
-    m_numFramesPending++;
+    if (m_swapBuffersCompleteSupported)
+        m_numFramesPending++;
+    else if (!m_isTimeSourceThrottling)
+        postManualTick();
 }
 
 void CCFrameRateController::didFinishFrame()
 {
+    ASSERT(m_swapBuffersCompleteSupported);
+
     m_numFramesPending--;
     if (!m_isTimeSourceThrottling)
         postManualTick();