Improve layers repaint speed.

Computing the layers texture size is heavy; we delay this
computation if one was done recently.

bug:3375416
Change-Id: I0ce79cdfcaa15cd1521370a1d5b8df5a5e5ea2c5

4 files changed, 20 insertions, 15 deletions

diff --git a/WebCore/platform/graphics/android/BaseLayerAndroid.cpp b/WebCore/platform/graphics/android/BaseLayerAndroid.cpp
index 2f0e999..35c3b36 100644
--- a/WebCore/platform/graphics/android/BaseLayerAndroid.cpp
+++ b/WebCore/platform/graphics/android/BaseLayerAndroid.cpp
@@ -116,12 +116,11 @@ void BaseLayerAndroid::drawCanvas(SkCanvas* canvas)
 }
 
 #if USE(ACCELERATED_COMPOSITING)
-bool BaseLayerAndroid::drawBasePictureInGL(SkRect& viewport, float scale)
+bool BaseLayerAndroid::drawBasePictureInGL(SkRect& viewport, float scale, double currentTime)
 {
     if (!m_glWebViewState)
         return false;
 
-    double currentTime = WTF::currentTime();
     bool goingDown = m_previousVisible.fTop - viewport.fTop <= 0;
     bool goingLeft = m_previousVisible.fLeft - viewport.fLeft >= 0;
 
@@ -282,7 +281,8 @@ bool BaseLayerAndroid::drawGL(IntRect& viewRect, SkRect& visibleRect,
     shader->setViewRect(viewRect);
     shader->setViewport(visibleRect);
 
-    ret = drawBasePictureInGL(visibleRect, scale);
+    double currentTime = WTF::currentTime();
+    ret = drawBasePictureInGL(visibleRect, scale, currentTime);
 
     if (countChildren() >= 1) {
         LayerAndroid* compositedRoot = static_cast<LayerAndroid*>(getChild(0));
@@ -311,7 +311,7 @@ bool BaseLayerAndroid::drawGL(IntRect& viewRect, SkRect& visibleRect,
             scale = m_glWebViewState->futureScale();
         }
         compositedRoot->setScale(scale);
-        compositedRoot->computeTextureSize();
+        compositedRoot->computeTextureSize(currentTime);
         compositedRoot->reserveGLTextures();
 
 #ifdef DEBUG
@@ -337,12 +337,6 @@ bool BaseLayerAndroid::drawGL(IntRect& viewRect, SkRect& visibleRect,
     glBindBuffer(GL_ARRAY_BUFFER, 0);
     m_previousVisible = visibleRect;
 
-#ifdef DEBUG_COUNT
-    XLOG("GLWebViewState(%d) DoubleBufferedTexture(%d) BaseTile(%d) TileSet(%d) TiledPage(%d)",
-         GLWebViewState::count(), DoubleBufferedTexture::count(),
-         BaseTile::count(), TileSet::count(), TiledPage::count());
-#endif // DEBUG_COUNT
-
 #endif // USE(ACCELERATED_COMPOSITING)
 #ifdef DEBUG
     ClassTracker::instance()->show();
diff --git a/WebCore/platform/graphics/android/BaseLayerAndroid.h b/WebCore/platform/graphics/android/BaseLayerAndroid.h
index c57b13d..cb1caef 100644
--- a/WebCore/platform/graphics/android/BaseLayerAndroid.h
+++ b/WebCore/platform/graphics/android/BaseLayerAndroid.h
@@ -59,7 +59,7 @@ public:
     void swapExtra(BaseLayerAndroid* base) { m_extra.swap(base->m_extra); }
 private:
 #if USE(ACCELERATED_COMPOSITING)
-    bool drawBasePictureInGL(SkRect& viewport, float scale);
+    bool drawBasePictureInGL(SkRect& viewport, float scale, double currentTime);
 
     GLWebViewState* m_glWebViewState;
     android::Mutex m_drawLock;
diff --git a/WebCore/platform/graphics/android/LayerAndroid.cpp b/WebCore/platform/graphics/android/LayerAndroid.cpp
index bee423c..7375cba 100644
--- a/WebCore/platform/graphics/android/LayerAndroid.cpp
+++ b/WebCore/platform/graphics/android/LayerAndroid.cpp
@@ -75,7 +75,8 @@ LayerAndroid::LayerAndroid(bool isRootLayer) : SkLayer(),
     m_reservedTexture(0),
     m_pictureUsed(0),
     m_requestSent(false),
-    m_scale(1)
+    m_scale(1),
+    m_lastComputeTextureSize(0)
 {
     m_backgroundColor = 0;
 
@@ -123,6 +124,7 @@ LayerAndroid::LayerAndroid(const LayerAndroid& layer) : SkLayer(layer),
     m_dirty = layer.m_dirty;
     m_pictureUsed = layer.m_pictureUsed;
     m_scale = layer.m_scale;
+    m_lastComputeTextureSize = 0;
 
     for (int i = 0; i < layer.countChildren(); i++)
         addChild(layer.getChild(i)->copy())->unref();
@@ -147,7 +149,8 @@ LayerAndroid::LayerAndroid(SkPicture* picture) : SkLayer(),
     m_drawingTexture(0),
     m_reservedTexture(0),
     m_requestSent(false),
-    m_scale(1)
+    m_scale(1),
+    m_lastComputeTextureSize(0)
 {
     m_backgroundColor = 0;
     m_dirty = false;
@@ -651,8 +654,12 @@ static inline bool compareLayerFullSize(const LayerAndroid* a, const LayerAndroi
     return sizeA > sizeB;
 }
 
-void LayerAndroid::computeTextureSize()
+void LayerAndroid::computeTextureSize(double time)
 {
+   if (m_lastComputeTextureSize + s_computeTextureDelay > time)
+       return;
+   m_lastComputeTextureSize = time;
+
    // First, we collect the layers, computing m_layerTextureRect
    // as being clipped against the viewport
    Vector <LayerAndroid*> layers;
diff --git a/WebCore/platform/graphics/android/LayerAndroid.h b/WebCore/platform/graphics/android/LayerAndroid.h
index 2cb56c1..0d5a878 100644
--- a/WebCore/platform/graphics/android/LayerAndroid.h
+++ b/WebCore/platform/graphics/android/LayerAndroid.h
@@ -111,7 +111,7 @@ public:
     void showLayers(int indent = 0);
 
     // Texture size functions
-    void computeTextureSize();
+    void computeTextureSize(double time);
     void collect(Vector<LayerAndroid*>& layers,
                  int& size);
     int clippedTextureSize() const;
@@ -325,6 +325,10 @@ private:
 
     float m_scale;
 
+    // We try to not always compute the texture size, as this is quite heavy
+    static const double s_computeTextureDelay = 0.2; // 200 ms
+    double m_lastComputeTextureSize;
+
     // This mutex serves two purposes. (1) It ensures that certain operations
     // happen atomically and (2) it makes sure those operations are synchronized
     // across all threads and cores.