Add tree swapping properties and stats

Change-Id: I0033b8794ae33dade050069d6c209653f0d21fd1

3 files changed, 24 insertions, 3 deletions

diff --git a/Source/WebCore/platform/graphics/android/TilesManager.cpp b/Source/WebCore/platform/graphics/android/TilesManager.cpp
index fbf7ae6..cbbbe5c 100644
--- a/Source/WebCore/platform/graphics/android/TilesManager.cpp
+++ b/Source/WebCore/platform/graphics/android/TilesManager.cpp
@@ -103,6 +103,8 @@ TilesManager::TilesManager()
     , m_invertedScreen(false)
     , m_invertedScreenSwitch(false)
     , m_useMinimalMemory(true)
+    , m_useDoubleBuffering(true)
+    , m_treeUpdates(0)
     , m_drawGLCount(1)
     , m_lastTimeLayersUsed(0)
     , m_hasLayerTextures(false)
diff --git a/Source/WebCore/platform/graphics/android/TilesManager.h b/Source/WebCore/platform/graphics/android/TilesManager.h
index f798196..dd01fc5 100644
--- a/Source/WebCore/platform/graphics/android/TilesManager.h
+++ b/Source/WebCore/platform/graphics/android/TilesManager.h
@@ -178,6 +178,16 @@ public:
         return m_useMinimalMemory;
     }
 
+    void setUseDoubleBuffering(bool useDoubleBuffering)
+    {
+        m_useDoubleBuffering = useDoubleBuffering;
+    }
+    bool useDoubleBuffering() { return m_useDoubleBuffering; }
+
+    void incTreeUpdates() { m_treeUpdates++; }
+    unsigned int getTreeUpdates() { return m_treeUpdates; }
+    void clearTreeUpdates() { m_treeUpdates = 0; }
+
     void incDrawGLCount()
     {
         m_drawGLCount++;
@@ -227,6 +237,9 @@ private:
 
     bool m_useMinimalMemory;
 
+    bool m_useDoubleBuffering;
+    unsigned int m_treeUpdates;
+
     sp<TexturesGenerator> m_pixmapsGenerationThread;
 
     android::Mutex m_texturesLock;
diff --git a/Source/WebCore/platform/graphics/android/TreeManager.cpp b/Source/WebCore/platform/graphics/android/TreeManager.cpp
index 35ddeb8..be161a0 100644
--- a/Source/WebCore/platform/graphics/android/TreeManager.cpp
+++ b/Source/WebCore/platform/graphics/android/TreeManager.cpp
@@ -159,10 +159,15 @@ void TreeManager::updateWithTree(Layer* newTree, bool brandNew)
     if (m_queuedTree || m_paintingTree) {
         // currently painting, so defer this new tree
         if (m_queuedTree) {
-            // have a queued tree, copy over invals so the regions are
-            // eventually repainted
+            // already have a queued tree, copy over invals so the regions are
+            // eventually repainted and let the old queued tree be discarded
             m_queuedTree->mergeInvalsInto(newTree);
 
+            if (!TilesManager::instance()->useDoubleBuffering()) {
+                // not double buffering, count discarded tree/webkit paint as an update
+                TilesManager::instance()->incTreeUpdates();
+            }
+
             XLOG("DISCARDING tree - %p, has children %d, has animations %d",
                  newTree, newTree && newTree->countChildren(),
                  newTree && newTree->countChildren()
@@ -222,9 +227,10 @@ bool TreeManager::drawGL(double currentTime, IntRect& viewRect,
         if (laTree)
             laTree->computeTexturesAmount(texturesResultPtr);
 
-        if (/*!m_fastSwapMode && */ m_paintingTree->isReady()) {
+        if (!TilesManager::instance()->useDoubleBuffering() || m_paintingTree->isReady()) {
             XLOG("have painting tree %p ready, swapping!", m_paintingTree);
             didTreeSwap = true;
+            TilesManager::instance()->incTreeUpdates();
             swap();
             if (treesSwappedPtr)
                 *treesSwappedPtr = true;