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

cc/layer_tree_host.cc

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/layer_tree_host.h"
 
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/message_loop.h"
 #include "base/stl_util.h"
@@ skipping 10 matching lines @@
 #include "cc/layer_tree_host_impl.h"
 #include "cc/layer_tree_impl.h"
 #include "cc/math_util.h"
 #include "cc/occlusion_tracker.h"
 #include "cc/overdraw_metrics.h"
 #include "cc/prioritized_resource_manager.h"
 #include "cc/single_thread_proxy.h"
 #include "cc/switches.h"
 #include "cc/thread.h"
 #include "cc/thread_proxy.h"
+#include "cc/top_controls_manager.h"
 #include "cc/tree_synchronizer.h"
 
 namespace {
 static int numLayerTreeInstances;
 }
 
 namespace cc {
 
 bool LayerTreeHost::s_needsFilterContext = false;
 
@@ skipping 287 matching lines @@
 
     syncTree->set_source_frame_number(commitNumber());
     syncTree->set_background_color(m_backgroundColor);
     syncTree->set_has_transparent_background(m_hasTransparentBackground);
 
     hostImpl->setViewportSize(layoutViewportSize(), deviceViewportSize());
     hostImpl->setDeviceScaleFactor(deviceScaleFactor());
     hostImpl->setPageScaleFactorAndLimits(m_pageScaleFactor, m_minPageScaleFactor, m_maxPageScaleFactor);
     hostImpl->setDebugState(m_debugState);
 
+    if (m_settings.calculateTopControlsPosition && m_topControlsContentLayer && hostImpl->topControlsManager())
+        hostImpl->topControlsManager()->set_content_layer_id(m_topControlsContentLayer->id());
+
     m_commitNumber++;
 }
 
 void LayerTreeHost::willCommit()
 {
     m_client->willCommit();
 
     if (m_debugState.showHudInfo()) {
         if (!m_hudLayer)
             m_hudLayer = HeadsUpDisplayLayer::create();
@@ skipping 118 matching lines @@
         return;
 
     if (m_rootLayer)
         m_rootLayer->setLayerTreeHost(0);
     m_rootLayer = rootLayer;
     if (m_rootLayer)
         m_rootLayer->setLayerTreeHost(this);
 
     if (m_hudLayer)
         m_hudLayer->removeFromParent();
+    if (m_topControlsContentLayer)
+        m_topControlsContentLayer->removeFromParent();
 
     setNeedsFullTreeSync();
 }
 
 void LayerTreeHost::setDebugState(const LayerTreeDebugState& debugState)
 {
     LayerTreeDebugState newDebugState = LayerTreeDebugState::unite(m_settings.initialDebugState, debugState);
 
     if (LayerTreeDebugState::equal(m_debugState, newDebugState))
         return;
@@ skipping 76 matching lines @@
 
     if (!rootLayer())
         return;
 
     if (layoutViewportSize().IsEmpty())
         return;
 
     if (memoryAllocationLimitBytes)
         m_contentsTextureManager->setMaxMemoryLimitBytes(memoryAllocationLimitBytes);
 
+    if (m_settings.calculateTopControlsPosition) {
+        if (!m_topControlsContentLayer) {
+            m_topControlsContentLayer = Layer::create();
+            m_topControlsContentLayer->setIsDrawable(false);

[enne (OOO), 2013/01/12 00:15:00]

Can you add a setDebugName("Top Controls Content") or some such here?

Also, did you have a chance to try calling
setIsContainerForFixedPositionLayers(true) and see if that fixed your fixed
position woes too?

[Ted C, 2013/01/12 01:23:05]

Done.

+        }
+
+        // Insert a layer that allows the top controls manager to move around
+        // the content without clobbering/being clobbered by other transforms.
+        if (!LayerTreeHostCommon::findLayerInSubtree(m_rootLayer.get(), m_topControlsContentLayer->id())) {
+            m_topControlsContentLayer->setLayerTreeHost(m_rootLayer->layerTreeHost());
+            m_topControlsContentLayer->setChildren(m_rootLayer->children());
+            m_rootLayer->addChild(m_topControlsContentLayer);
+        }
+    }
+
     updateLayers(rootLayer(), queue);
 }
 
 static Layer* findFirstScrollableLayer(Layer* layer)
 {
     if (!layer)
         return 0;
 
     if (layer->scrollable())
         return layer;
@@ skipping 307 matching lines @@
     for (size_t childIndex = 0; childIndex < layer->children().size(); ++childIndex)
         setAnimationEventsRecursive(events, layer->children()[childIndex].get(), wallClockTime);
 }
 
 skia::RefPtr<SkPicture> LayerTreeHost::capturePicture()
 {
     return m_proxy->capturePicture();
 }
 
 }  // namespace cc