DO NOT MERGE priority queue based tile manager

 Removes TileSets and queues tiles individually
 Uses a priority queue to determine which tiles to render first
 Stops rendering the front tile page if we are prepping the back one
 Limits queue spam by tracking which tiles are already in the queue

Change-Id: Idd4154b8a2771d0db2da94c84a683314597f8542

1 files changed, 9 insertions, 5 deletions

diff --git a/WebCore/platform/graphics/android/BaseLayerAndroid.cpp b/WebCore/platform/graphics/android/BaseLayerAndroid.cpp
index c59a5a5..c61a09a 100644
--- a/WebCore/platform/graphics/android/BaseLayerAndroid.cpp
+++ b/WebCore/platform/graphics/android/BaseLayerAndroid.cpp
@@ -163,13 +163,19 @@ bool BaseLayerAndroid::drawBasePictureInGL(SkRect& viewport, float scale, double
         zooming = true;
     }
 
+    // Display the current page
+    TiledPage* tiledPage = m_glWebViewState->frontPage();
+    tiledPage->setScale(m_glWebViewState->currentScale());
+
     // Let's prepare the page if needed
     if (prepareNextTiledPage) {
         TiledPage* nextTiledPage = m_glWebViewState->backPage();
         nextTiledPage->setScale(scale);
         m_glWebViewState->setFutureViewport(viewportTileBounds);
         m_glWebViewState->lockBaseLayerUpdate();
-        nextTiledPage->prepare(goingDown, goingLeft, viewportTileBounds, true);
+        nextTiledPage->prepare(goingDown, goingLeft, viewportTileBounds);
+        // Cancel pending paints for the foreground page
+        TilesManager::instance()->removePaintOperationsForPage(tiledPage, false);
     }
 
     float transparency = 1;
@@ -205,9 +211,6 @@ bool BaseLayerAndroid::drawBasePictureInGL(SkRect& viewport, float scale, double
         }
     }
 
-    // Display the current page
-    TiledPage* tiledPage = m_glWebViewState->frontPage();
-    tiledPage->setScale(m_glWebViewState->currentScale());
     const SkIRect& preZoomBounds = m_glWebViewState->preZoomBounds();
 
     TiledPage* nextTiledPage = m_glWebViewState->backPage();
@@ -240,7 +243,8 @@ bool BaseLayerAndroid::drawBasePictureInGL(SkRect& viewport, float scale, double
         if (!zooming)
            m_glWebViewState->unlockBaseLayerUpdate();
 
-        tiledPage->prepare(goingDown, goingLeft, preZoomBounds, true);
+        if (!prepareNextTiledPage)
+            tiledPage->prepare(goingDown, goingLeft, preZoomBounds);
         tiledPage->draw(transparency, preZoomBounds);
     }