[cc] Fold more update calls into updateDrawProperties

cc/layer_tree_host_impl.cc

Index: cc/layer_tree_host_impl.cc
diff --git a/cc/layer_tree_host_impl.cc b/cc/layer_tree_host_impl.cc
index 034ef0815e638802263b18c34f47d88f54ad2219..0dc38f8bbd7afd9a8fcdd69829c18c86ba1a747d 100644
--- a/cc/layer_tree_host_impl.cc
+++ b/cc/layer_tree_host_impl.cc
@@ -380,13 +380,6 @@ void LayerTreeHostImpl::trackDamageForAllSurfaces(LayerImpl* rootDrawLayer, cons
     }
 }
 
-void LayerTreeHostImpl::updateRootScrollLayerImplTransform()
-{
-    if (rootScrollLayer()) {
-        rootScrollLayer()->setImplTransform(implTransform());
-    }
-}
-
 void LayerTreeHostImpl::updateDrawProperties()
 {
     if (!needsUpdateDrawProperties())
@@ -398,20 +391,16 @@ void LayerTreeHostImpl::updateDrawProperties()
     if (!rootLayer())
         return;
 
-    calculateRenderSurfaceLayerList(m_renderSurfaceLayerList);
-}
+    if (!m_renderer) // For maxTextureSize.
+      return;
 
-void LayerTreeHostImpl::calculateRenderSurfaceLayerList(LayerList& renderSurfaceLayerList)
-{
-    DCHECK(renderSurfaceLayerList.empty());
-    DCHECK(rootLayer());
-    DCHECK(m_renderer); // For maxTextureSize.
-    {
-        updateRootScrollLayerImplTransform();
+    if (rootScrollLayer())
+      rootScrollLayer()->setImplTransform(implTransform());
 
-        TRACE_EVENT0("cc", "LayerTreeHostImpl::calcDrawEtc");
-        float pageScaleFactor = m_pinchZoomViewport.pageScaleFactor();
-        LayerTreeHostCommon::calculateDrawProperties(rootLayer(), deviceViewportSize(), m_deviceScaleFactor, pageScaleFactor, rendererCapabilities().maxTextureSize, renderSurfaceLayerList);
+    {
+      TRACE_EVENT0("cc", "LayerTreeHostImpl::calcDrawEtc");
+      float pageScaleFactor = m_pinchZoomViewport.pageScaleFactor();
+      LayerTreeHostCommon::calculateDrawProperties(rootLayer(), deviceViewportSize(), m_deviceScaleFactor, pageScaleFactor, rendererCapabilities().maxTextureSize, m_renderSurfaceLayerList);
     }
 }
 
@@ -512,6 +501,9 @@ bool LayerTreeHostImpl::calculateRenderPasses(FrameData& frame)
     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()));
@@ -766,7 +758,6 @@ void LayerTreeHostImpl::removeRenderPasses(RenderPassCuller culler, FrameData& f
 bool LayerTreeHostImpl::prepareToDraw(FrameData& frame)
 {
     TRACE_EVENT0("cc", "LayerTreeHostImpl::prepareToDraw");
-    DCHECK(canDraw());

[danakj, 2012/12/13 00:03:37]

I don't like this.. I assume this is for the tests. Can they just set a viewport
size or whatever is making canDraw() false?

[enne (OOO), 2012/12/13 00:18:07]

I'm going to disagree here.  I like this a lot.  The amount of setup you need to
do to get a test on a layer tree seems overly burdensome.  We call prepareToDraw
in exactly two non-test locations, so I'm not that sure this assert is buying us
very much.

[danakj, 2012/12/13 00:20:15]

I am motivated by the fact that we had a lot of crashes in the past which is why
it's here :/

Maybe we need a TestLayerTreeHostImpl that lets you force canDraw to always be
true or something.

 
     if (m_tileManager)
         m_tileManager->CheckForCompletedSetPixels();
@@ -903,7 +894,8 @@ void LayerTreeHostImpl::didDrawAllLayers(const FrameData& frame)
 
     // Once all layers have been drawn, pending texture uploads should no
     // longer block future uploads.
-    m_resourceProvider->markPendingUploadsAsNonBlocking();
+    if (m_resourceProvider)

[danakj, 2012/12/13 00:03:37]

If we initialze the host properly with a FakeOutputSurface this shouldn't be
needed?

The Setup() function in LTHImplTests does this.

+      m_resourceProvider->markPendingUploadsAsNonBlocking();
 }
 
 void LayerTreeHostImpl::finishAllRendering()
@@ -1190,25 +1182,7 @@ void LayerTreeHostImpl::setNeedsRedraw()
 
 bool LayerTreeHostImpl::ensureRenderSurfaceLayerList()
 {
-    // TODO(enne): See http://crbug.com/164949.  This function should really

[danakj, 2012/12/13 00:03:37]

This is super yay.

-    // 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();
 }