Adaptively throttle texture uploads

cc/CCSingleThreadProxy.cpp

Index: cc/CCSingleThreadProxy.cpp
diff --git a/cc/CCSingleThreadProxy.cpp b/cc/CCSingleThreadProxy.cpp
index f6d4f67f1a9cb60c058611abbc39c5f57cc775e2..a373fc6ee61e9275b1d77e14688babff999bfa49 100644
--- a/cc/CCSingleThreadProxy.cpp
+++ b/cc/CCSingleThreadProxy.cpp
@@ -16,6 +16,13 @@
 
 using namespace WTF;
 
+namespace {
+
+// We don't need to split texture uploads into multiple batches if we are single threaded.
+const size_t maxTextureUpdates = std::numeric_limits<size_t>::max();
+
+}
+
 namespace WebCore {
 
 PassOwnPtr<CCProxy> CCSingleThreadProxy::create(CCLayerTreeHost* layerTreeHost)
@@ -28,6 +35,8 @@ CCSingleThreadProxy::CCSingleThreadProxy(CCLayerTreeHost* layerTreeHost)
     , m_contextLost(false)
     , m_rendererInitialized(false)
     , m_nextFrameIsNewlyCommittedFrame(false)
+    , m_totalCommitTime(0)
+    , m_totalCommitCount(0)
 {
     TRACE_EVENT0("cc", "CCSingleThreadProxy::CCSingleThreadProxy");
     ASSERT(CCProxy::isMainThread());
@@ -150,8 +159,10 @@ bool CCSingleThreadProxy::recreateContext()
     return initialized;
 }
 
-void CCSingleThreadProxy::implSideRenderingStats(CCRenderingStats& stats)
+void CCSingleThreadProxy::renderingStats(CCRenderingStats& stats)
 {
+    stats.totalCommitTimeInSeconds = m_totalCommitTime;
+    stats.totalCommitCount = m_totalCommitCount;
     m_layerTreeHostImpl->renderingStats(stats);
 }
 
@@ -183,6 +194,7 @@ void CCSingleThreadProxy::doCommit(CCTextureUpdateQueue& queue)
         DebugScopedSetMainThreadBlocked mainThreadBlocked;
         DebugScopedSetImplThread impl;
 
+        double startTime = WTF::monotonicallyIncreasingTime();
         m_layerTreeHostImpl->beginCommit();
 
         m_layerTreeHost->beginCommitOnImplThread(m_layerTreeHostImpl.get());
@@ -193,7 +205,7 @@ void CCSingleThreadProxy::doCommit(CCTextureUpdateQueue& queue)
         // single thread mode. For correctness, loop until no more updates are
         // pending.
         while (queue.hasMoreUpdates())
-            CCTextureUpdateController::updateTextures(m_layerTreeHostImpl->resourceProvider(), m_layerTreeHostImpl->renderer()->textureCopier(), m_layerTreeHostImpl->renderer()->textureUploader(), &queue, maxPartialTextureUpdates());
+            CCTextureUpdateController::updateTextures(m_layerTreeHostImpl->resourceProvider(), m_layerTreeHostImpl->renderer()->textureCopier(), m_layerTreeHostImpl->renderer()->textureUploader(), &queue, maxTextureUpdates);
 
         m_layerTreeHost->finishCommitOnImplThread(m_layerTreeHostImpl.get());
 
@@ -205,6 +217,11 @@ void CCSingleThreadProxy::doCommit(CCTextureUpdateQueue& queue)
         OwnPtr<CCScrollAndScaleSet> scrollInfo = m_layerTreeHostImpl->processScrollDeltas();
         ASSERT(!scrollInfo->scrolls.size());
 #endif
+
+        double endTime = WTF::monotonicallyIncreasingTime();
+        double commitTime = endTime - startTime;
+        m_totalCommitTime += commitTime;
+        m_totalCommitCount++;
     }
     m_layerTreeHost->commitComplete();
     m_nextFrameIsNewlyCommittedFrame = true;
@@ -287,7 +304,7 @@ bool CCSingleThreadProxy::commitAndComposite()
     }
 
     CCTextureUpdateQueue queue;
-    m_layerTreeHost->updateLayers(queue, m_layerTreeHostImpl->memoryAllocationLimitBytes());
+    m_layerTreeHost->updateLayers(queue, m_layerTreeHostImpl->memoryAllocationLimitBytes(), maxTextureUpdates);
     m_layerTreeHostImpl->resetContentsTexturesPurged();
 
     m_layerTreeHost->willCommit();