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 22995bbe4c8ad0f02295c5c6c3ec86bc3c6ffe4d..f759a1b1916bcad310bbbc645bd89fc85607363c 100644
--- a/cc/layer_tree_host_impl.cc
+++ b/cc/layer_tree_host_impl.cc
@@ -37,6 +37,7 @@
 #include "cc/software_renderer.h"
 #include "cc/solid_color_draw_quad.h"
 #include "cc/texture_uploader.h"
+#include "cc/top_controls_manager.h"
 #include "cc/util.h"
 #include "ui/gfx/size_conversions.h"
 #include "ui/gfx/vector2d_conversions.h"
@@ -136,6 +137,9 @@ LayerTreeHostImpl::LayerTreeHostImpl(const LayerTreeSettings& settings, LayerTre
     DCHECK(m_proxy->isImplThread());
     didVisibilityChange(this, m_visible);
 
+    if (settings.calculateTopControlsPosition)
+        m_topControlsManager = TopControlsManager::Create(this, settings.topControlsHeightPx);
+
     // LTHI always has an active tree.
     m_activeTree = LayerTreeImpl::create(this);
 }
@@ -219,6 +223,8 @@ void LayerTreeHostImpl::animate(base::TimeTicks monotonicTime, base::Time wallCl
     animatePageScale(monotonicTime);
     animateLayers(monotonicTime, wallClockTime);
     animateScrollbars(monotonicTime);
+    if (m_topControlsManager)
+        m_topControlsManager->Animate(monotonicTime);
 }
 
 void LayerTreeHostImpl::manageTiles()
@@ -320,6 +326,8 @@ void LayerTreeHostImpl::updateDrawProperties()
       return;
     }
 
+    if (m_topControlsManager)
+      m_topControlsManager->UpdateDrawPositions();
     activeTree()->UpdateDrawProperties();
     if (pendingTree())
       pendingTree()->UpdateDrawProperties();
@@ -772,6 +780,10 @@ CompositorFrameMetadata LayerTreeHostImpl::makeCompositorFrameMetadata() const
     metadata.root_layer_size = contentSize();
     metadata.min_page_scale_factor = m_pinchZoomViewport.min_page_scale_factor();
     metadata.max_page_scale_factor = m_pinchZoomViewport.max_page_scale_factor();
+    if (m_topControlsManager) {
+        metadata.location_bar_offset = gfx::Vector2dF(0.f, m_topControlsManager->controls_top_offset());
+        metadata.content_offset = gfx::Vector2dF(0.f, m_topControlsManager->content_top_offset());
+    }
 
     return metadata;
 }
@@ -898,6 +910,11 @@ static LayerImpl* findScrollLayerForContentLayer(LayerImpl* layerImpl)
     return 0;
 }
 
+LayerTreeImpl* LayerTreeHostImpl::activeTree()
+{
+    return m_activeTree.get();
+}
+
 void LayerTreeHostImpl::createPendingTree()
 {
     CHECK(!m_pendingTree);
@@ -1090,6 +1107,11 @@ void LayerTreeHostImpl::updateMaxScrollOffset()
         pendingTree()->UpdateMaxScrollOffset();
 }
 
+void LayerTreeHostImpl::setNeedsUpdateDrawProperties()
+{
+    m_needsUpdateDrawProperties = true;
+}
+
 void LayerTreeHostImpl::setNeedsRedraw()
 {
     m_client->setNeedsRedrawOnImplThread();
@@ -1105,6 +1127,9 @@ InputHandlerClient::ScrollStatus LayerTreeHostImpl::scrollBegin(gfx::Point viewp
 {
     TRACE_EVENT0("cc", "LayerTreeHostImpl::scrollBegin");
 
+    if (m_topControlsManager)
+        m_topControlsManager->ScrollBegin();
+
     DCHECK(!currentlyScrollingLayer());
     clearCurrentlyScrollingLayer();
 
@@ -1237,6 +1262,9 @@ bool LayerTreeHostImpl::scrollBy(const gfx::Point& viewportPoint,
         if (m_settings.pageScalePinchZoomEnabled && layerImpl == rootScrollLayer())
             viewport = &m_pinchZoomViewport;
         gfx::Vector2dF appliedDelta;
+        if (m_topControlsManager && layerImpl == rootScrollLayer())
+            pendingDelta = m_topControlsManager->ScrollBy(pendingDelta);
+
         if (m_scrollDeltaIsInViewportSpace) {
             float scaleFromViewportToScreenSpace = m_deviceScaleFactor;
             appliedDelta = scrollLayerWithViewportSpaceDelta(viewport, *layerImpl, scaleFromViewportToScreenSpace, viewportPoint, pendingDelta);
@@ -1281,6 +1309,8 @@ void LayerTreeHostImpl::clearCurrentlyScrollingLayer()
 
 void LayerTreeHostImpl::scrollEnd()
 {
+    if (m_topControlsManager)
+        m_topControlsManager->ScrollEnd();
     clearCurrentlyScrollingLayer();
 }