Revert 173406 - Crashes on Win & Mac

cc/layer_tree_host_impl.cc

Index: cc/layer_tree_host_impl.cc
===================================================================
--- cc/layer_tree_host_impl.cc	(revision 173406)
+++ cc/layer_tree_host_impl.cc	(working copy)
@@ -383,6 +383,13 @@
     }
 }
 
+void LayerTreeHostImpl::updateRootScrollLayerImplTransform()
+{
+    if (rootScrollLayer()) {
+        rootScrollLayer()->setImplTransform(implTransform());
+    }
+}
+
 void LayerTreeHostImpl::updateDrawProperties()
 {
     if (!needsUpdateDrawProperties())
@@ -394,16 +401,20 @@
     if (!rootLayer())
         return;
 
-    if (!m_renderer) // For maxTextureSize.
-      return;
+    calculateRenderSurfaceLayerList(m_renderSurfaceLayerList);
+}
 
-    if (rootScrollLayer())
-      rootScrollLayer()->setImplTransform(implTransform());
+void LayerTreeHostImpl::calculateRenderSurfaceLayerList(LayerList& renderSurfaceLayerList)
+{
+    DCHECK(renderSurfaceLayerList.empty());
+    DCHECK(rootLayer());
+    DCHECK(m_renderer); // For maxTextureSize.
+    {
+        updateRootScrollLayerImplTransform();
 
-    {
         TRACE_EVENT0("cc", "LayerTreeHostImpl::calcDrawEtc");
         float pageScaleFactor = m_pinchZoomViewport.pageScaleFactor();
-        LayerTreeHostCommon::calculateDrawProperties(rootLayer(), deviceViewportSize(), m_deviceScaleFactor, pageScaleFactor, rendererCapabilities().maxTextureSize, m_settings.canUseLCDText, m_renderSurfaceLayerList);
+        LayerTreeHostCommon::calculateDrawProperties(rootLayer(), deviceViewportSize(), m_deviceScaleFactor, pageScaleFactor, rendererCapabilities().maxTextureSize, m_settings.canUseLCDText, renderSurfaceLayerList);
     }
 }
 
@@ -504,9 +515,6 @@
     DCHECK(frame.renderPasses.empty());
 
     updateDrawProperties();
-    if (!canDraw())
-      return false;
-
     trackDamageForAllSurfaces(rootLayer(), *frame.renderSurfaceLayerList);
 
     TRACE_EVENT1("cc", "LayerTreeHostImpl::calculateRenderPasses", "renderSurfaceLayerList.size()", static_cast<long long unsigned>(frame.renderSurfaceLayerList->size()));
@@ -769,6 +777,7 @@
 bool LayerTreeHostImpl::prepareToDraw(FrameData& frame)
 {
     TRACE_EVENT0("cc", "LayerTreeHostImpl::prepareToDraw");
+    DCHECK(canDraw());
 
     if (m_tileManager)
         m_tileManager->CheckForCompletedSetPixels();
@@ -1197,7 +1206,25 @@
 
 bool LayerTreeHostImpl::ensureRenderSurfaceLayerList()
 {
+    // TODO(enne): See http://crbug.com/164949.  This function should really
+    // just call updateDrawProperties(), but that breaks a number of
+    // impl transform tests that don't expect the tree to be updated.
+    if (!rootLayer())
+        return false;
+    if (!m_renderer)
+        return false;
+
+    // We need both a non-empty render surface layer list and a root render
+    // surface to be able to iterate over the visible layers.
+    if (m_renderSurfaceLayerList.size() && rootLayer()->renderSurface())
+        return true;
+
+    // If we are called after setRootLayer() but before prepareToDraw(), we need
+    // to recalculate the visible layers. This prevents being unable to scroll
+    // during part of a commit.
+    setNeedsUpdateDrawProperties();
     updateDrawProperties();
+
     return m_renderSurfaceLayerList.size();
 }