Add support for calculating the position of the top controls in the cc layer.

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 740c361935199ca9b78617a1adece1e59db96d12..06ec54fde62102e43adedc053657ebc26aeff651 100644
--- a/cc/layer_tree_host_impl.cc
+++ b/cc/layer_tree_host_impl.cc
@@ -235,6 +235,7 @@ LayerTreeHostImpl::LayerTreeHostImpl(const LayerTreeSettings& settings, LayerTre
 {
     DCHECK(m_proxy->isImplThread());
     didVisibilityChange(this, m_visible);
+    m_topControlsManager = TopControlsManager::create(this, settings.calculateTopControlsPosition, settings.topControlsHeight);

[aelias_OOO_until_Jul13, 2012/12/19 08:31:18]

I don't think this object should be created at all when
calculateTopControlsPosition is disabled.  Just leave it null and protect all
uses of it with if (m_topControlsManager).  Then you also can get rid of the
"enabled" boolean inside the class.

[Ted C, 2012/12/19 21:34:17]

Done.

 
     // TODO(nduca): For now, assume we have an active tree. This will be removed
     // in future patches.
@@ -306,6 +307,7 @@ void LayerTreeHostImpl::animate(base::TimeTicks monotonicTime, base::Time wallCl
     animatePageScale(monotonicTime);
     animateLayers(monotonicTime, wallClockTime);
     animateScrollbars(monotonicTime);
+    m_topControlsManager->animate(monotonicTime);
 }
 
 void LayerTreeHostImpl::manageTiles()
@@ -415,6 +417,7 @@ void LayerTreeHostImpl::calculateRenderSurfaceLayerList(LayerList& renderSurface
 
         TRACE_EVENT0("cc", "LayerTreeHostImpl::calcDrawEtc");
         float pageScaleFactor = m_pinchZoomViewport.pageScaleFactor();
+        m_topControlsManager->updateDrawPositions();
         LayerTreeHostCommon::calculateDrawProperties(rootLayer(), deviceViewportSize(), m_deviceScaleFactor, pageScaleFactor, rendererCapabilities().maxTextureSize, m_settings.canUseLCDText, renderSurfaceLayerList);
     }
 }
@@ -898,6 +901,10 @@ CompositorFrameMetadata LayerTreeHostImpl::makeCompositorFrameMetadata() const
         metadata.root_scroll_offset.Scale(1 / m_pinchZoomViewport.pageScaleFactor());
         metadata.root_layer_size.Scale(1 / m_pinchZoomViewport.pageScaleFactor());
     }
+    if (m_settings.calculateTopControlsPosition) {
+        metadata.location_bar_offset = gfx::Point(0.f, m_topControlsManager->controls_top_offset());
+        metadata.content_offset = gfx::PointF(0.f, m_topControlsManager->content_top_offset());
+    }
 
     return metadata;
 }
@@ -1025,6 +1032,11 @@ static LayerImpl* findScrollLayerForContentLayer(LayerImpl* layerImpl)
     return 0;
 }
 
+LayerTreeImpl* LayerTreeHostImpl::activeTree()
+{
+    return m_activeTree.get();
+}
+
 void LayerTreeHostImpl::setRootLayer(scoped_ptr<LayerImpl> layer)
 {
     m_activeTree->SetRootLayer(layer.Pass());
@@ -1220,6 +1232,11 @@ void LayerTreeHostImpl::updateMaxScrollOffset()
     rootScrollLayer()->setMaxScrollOffset(gfx::ToFlooredVector2d(maxScroll));
 }
 
+void LayerTreeHostImpl::setNeedsUpdateDrawProperties()
+{
+    m_needsUpdateDrawProperties = true;
+}
+
 void LayerTreeHostImpl::setNeedsRedraw()
 {
     m_client->setNeedsRedrawOnImplThread();
@@ -1253,6 +1270,8 @@ InputHandlerClient::ScrollStatus LayerTreeHostImpl::scrollBegin(gfx::Point viewp
 {
     TRACE_EVENT0("cc", "LayerTreeHostImpl::scrollBegin");
 
+    m_topControlsManager->scrollBegin();
+
     DCHECK(!currentlyScrollingLayer());
     clearCurrentlyScrollingLayer();
 
@@ -1369,6 +1388,8 @@ bool LayerTreeHostImpl::scrollBy(const gfx::Point& viewportPoint,
     if (!currentlyScrollingLayer())
         return false;
 
+    m_topControlsManager->resetAnimations();
+
     gfx::Vector2dF pendingDelta = scrollDelta;
     bool didScroll = false;
 
@@ -1380,6 +1401,9 @@ bool LayerTreeHostImpl::scrollBy(const gfx::Point& viewportPoint,
         if (m_settings.pageScalePinchZoomEnabled && layerImpl == rootScrollLayer())
             viewport = &m_pinchZoomViewport;
         gfx::Vector2dF appliedDelta;
+        if (layerImpl == rootScrollLayer())
+            pendingDelta = m_topControlsManager->scrollBy(pendingDelta);
+
         if (m_scrollDeltaIsInViewportSpace) {
             float scaleFromViewportToScreenSpace = m_deviceScaleFactor;
             appliedDelta = scrollLayerWithViewportSpaceDelta(viewport, *layerImpl, scaleFromViewportToScreenSpace, viewportPoint, pendingDelta);
@@ -1424,6 +1448,7 @@ void LayerTreeHostImpl::clearCurrentlyScrollingLayer()
 
 void LayerTreeHostImpl::scrollEnd()
 {
+    m_topControlsManager->scrollEnd();
     clearCurrentlyScrollingLayer();
 }