[cc] Move root layer pointer to LayerTreeImpl

[cc] Move root layer pointer to LayerTreeImpl

This is the first of a series of patches to move tree-specific state from
LayerTreeHostImpl to LayerTreeImpl. The LayerTreeHostImpl has always been
imagined to be a "View" aka LayerTreeView(Impl) and will keep ahold of stuff
that is view-specific.  The LayerTreeImpl, in constrast, will store state that
is specific to a specific tree version.

BUG=155209
R=enne


Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=171593

[enne (OOO), 2012-12-05 23:09:09]

https://codereview.chromium.org/11450015/diff/1/cc/layer_tree_host.cc
File cc/layer_tree_host.cc (right):

https://codereview.chromium.org/11450015/diff/1/cc/layer_tree_host.cc#newcode386
cc/layer_tree_host.cc:386: hostImpl->setDeviceScaleFactor(deviceScaleFactor());
I kind of wonder if most of these other things are tree-specific state, since
they're tied to this commit.

Also, I'm assuming that all uses of activeTree() in this function will become
pendingTree() when that exists?

https://codereview.chromium.org/11450015/diff/1/cc/layer_tree_host_impl.cc
File cc/layer_tree_host_impl.cc (right):

https://codereview.chromium.org/11450015/diff/1/cc/layer_tree_host_impl.cc#ne...
cc/layer_tree_host_impl.cc:367: if (rootScrollLayer()) {
In the future are these sorts of calls just going to become two calls, one on
each tree?

https://codereview.chromium.org/11450015/diff/1/cc/layer_tree_host_impl.cc#ne...
cc/layer_tree_host_impl.cc:372: void
LayerTreeHostImpl::calculateRenderSurfaceLayerList(LayerList&
renderSurfaceLayerList)
I think this should move to LayerTreeImpl along with m_renderSurfaceLayerList.

[enne (OOO), 2012-12-06 17:32:30]

lgtm

layout bots still seem to pass, which is probably the thing I'd worry about most
with this patch.

I'm a little unclear about how testing is going to work in the future.  Maybe
LTHI-using unit tests can just have some mock tree that immediately says it's
ready and becomes active.

[commit-bot: I haz the power, 2012-12-06 18:05:29]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/nduca@chromium.org/11450015/5001

[commit-bot: I haz the power, 2012-12-06 18:05:44]

Failed to apply patch for cc/layer_tree_host_impl.cc:
While running patch -p1 --forward --force --no-backup-if-mismatch;
  patching file cc/layer_tree_host_impl.cc
  Hunk #7 FAILED at 380.
  Hunk #16 FAILED at 963.
  Hunk #23 FAILED at 1263.
  Hunk #24 succeeded at 1315 (offset 2 lines).
  Hunk #25 succeeded at 1328 (offset 2 lines).
  Hunk #26 succeeded at 1356 (offset 2 lines).
  Hunk #27 succeeded at 1369 (offset 2 lines).
  Hunk #28 succeeded at 1385 (offset 2 lines).
  Hunk #29 succeeded at 1397 (offset 2 lines).
  Hunk #30 succeeded at 1417 (offset 2 lines).
  Hunk #31 succeeded at 1463 (offset 2 lines).
  Hunk #32 succeeded at 1477 (offset 2 lines).
  Hunk #33 succeeded at 1486 (offset 2 lines).
  Hunk #34 succeeded at 1508 (offset 2 lines).
  Hunk #35 succeeded at 1516 (offset 2 lines).
  Hunk #36 succeeded at 1554 (offset 2 lines).
  Hunk #37 succeeded at 1597 (offset 2 lines).
  3 out of 37 hunks FAILED -- saving rejects to file
cc/layer_tree_host_impl.cc.rej

Patch:       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
8f32526fbc635f0ef6ac3375c45755e1b89b4618..cd4703495ab773fe0ae5820a613dd1718261b3a6
100644
--- a/cc/layer_tree_host_impl.cc
+++ b/cc/layer_tree_host_impl.cc
@@ -203,11 +203,6 @@ scoped_ptr<LayerTreeHostImpl>
LayerTreeHostImpl::create(const LayerTreeSettings&
 LayerTreeHostImpl::LayerTreeHostImpl(const LayerTreeSettings& settings,
LayerTreeHostImplClient* client, Proxy* proxy)
     : m_client(client)
     , m_proxy(proxy)
-    , m_sourceFrameNumber(-1)
-    , m_rootScrollLayerImpl(0)
-    , m_currentlyScrollingLayerImpl(0)
-    , m_hudLayerImpl(0)
-    , m_scrollingLayerIdFromPreviousTree(-1)
     , m_scrollDeltaIsInViewportSpace(false)
     , m_settings(settings)
     , m_debugState(settings.initialDebugState)
@@ -230,6 +225,10 @@ LayerTreeHostImpl::LayerTreeHostImpl(const
LayerTreeSettings& settings, LayerTre
 {
     DCHECK(m_proxy->isImplThread());
     didVisibilityChange(this, m_visible);
+
+    // TODO(nduca): For now, assume we have an active tree. This will be
removed
+    // in future patches.
+    m_activeTree = LayerTreeImpl::create(this);
 }
 
 LayerTreeHostImpl::~LayerTreeHostImpl()
@@ -237,7 +236,7 @@ LayerTreeHostImpl::~LayerTreeHostImpl()
     DCHECK(m_proxy->isImplThread());
     TRACE_EVENT0("cc", "LayerTreeHostImpl::~LayerTreeHostImpl()");
 
-    if (m_rootLayerImpl)
+    if (rootLayer())
         clearRenderSurfaces();
 }
 
@@ -260,7 +259,7 @@ bool LayerTreeHostImpl::canDraw()
     // affect the result of canDraw, make sure to call
m_client->onCanDrawStateChanged
     // in the proper places and update the notifyIfCanDrawChanged test.
 
-    if (!m_rootLayerImpl) {
+    if (!rootLayer()) {
         TRACE_EVENT_INSTANT0("cc", "LayerTreeHostImpl::canDraw no root layer");
         return false;
     }
@@ -299,10 +298,10 @@ void LayerTreeHostImpl::manageTiles()
 
 void LayerTreeHostImpl::startPageScaleAnimation(gfx::Vector2d targetOffset,
bool anchorPoint, float pageScale, base::TimeTicks startTime, base::TimeDelta
duration)
 {
-    if (!m_rootScrollLayerImpl)
+    if (!rootScrollLayer())
         return;
 
-    gfx::Vector2dF scrollTotal = m_rootScrollLayerImpl->scrollOffset() +
m_rootScrollLayerImpl->scrollDelta();
+    gfx::Vector2dF scrollTotal = rootScrollLayer()->scrollOffset() +
rootScrollLayer()->scrollDelta();
     gfx::SizeF scaledContentSize = contentSize();
     if (!m_settings.pageScalePinchZoomEnabled) {
         scrollTotal.Scale(1 / m_pinchZoomViewport.pageScaleFactor());
@@ -365,15 +364,15 @@ void
LayerTreeHostImpl::trackDamageForAllSurfaces(LayerImpl* rootDrawLayer, cons
 
 void LayerTreeHostImpl::updateRootScrollLayerImplTransform()
 {
-    if (m_rootScrollLayerImpl) {
-        m_rootScrollLayerImpl->setImplTransform(implTransform());
+    if (rootScrollLayer()) {
+        rootScrollLayer()->setImplTransform(implTransform());
     }
 }
 
 void LayerTreeHostImpl::calculateRenderSurfaceLayerList(LayerList&
renderSurfaceLayerList)
 {
     DCHECK(renderSurfaceLayerList.empty());
-    DCHECK(m_rootLayerImpl);
+    DCHECK(rootLayer());
     DCHECK(m_renderer); // For maxTextureSize.
 
     {
@@ -381,9 +380,9 @@ void
LayerTreeHostImpl::calculateRenderSurfaceLayerList(LayerList& renderSurface
 
         TRACE_EVENT0("cc", "LayerTreeHostImpl::calcDrawEtc");
         float pageScaleFactor = m_pinchZoomViewport.pageScaleFactor();
-        LayerTreeHostCommon::calculateDrawTransforms(m_rootLayerImpl.get(),
deviceViewportSize(), m_deviceScaleFactor, pageScaleFactor, &m_layerSorter,
rendererCapabilities().maxTextureSize, renderSurfaceLayerList);
+        LayerTreeHostCommon::calculateDrawTransforms(rootLayer(),
deviceViewportSize(), m_deviceScaleFactor, pageScaleFactor, &m_layerSorter,
rendererCapabilities().maxTextureSize, renderSurfaceLayerList);
 
-        trackDamageForAllSurfaces(m_rootLayerImpl.get(),
renderSurfaceLayerList);
+        trackDamageForAllSurfaces(rootLayer(), renderSurfaceLayerList);
     }
 }
 
@@ -494,7 +493,7 @@ bool LayerTreeHostImpl::calculateRenderPasses(FrameData&
frame)
     }
 
     bool recordMetricsForFrame = m_settings.showOverdrawInTracing &&
base::debug::TraceLog::GetInstance() &&
base::debug::TraceLog::GetInstance()->IsEnabled();
-    OcclusionTrackerImpl
occlusionTracker(m_rootLayerImpl->renderSurface()->contentRect(),
recordMetricsForFrame);
+    OcclusionTrackerImpl
occlusionTracker(rootLayer()->renderSurface()->contentRect(),
recordMetricsForFrame);
    
occlusionTracker.setMinimumTrackingSize(m_settings.minimumOcclusionTrackingSize);
 
     if (m_debugState.showOccludingRects)
@@ -572,7 +571,7 @@ bool LayerTreeHostImpl::calculateRenderPasses(FrameData&
frame)
 
     if (!m_hasTransparentBackground) {
         frame.renderPasses.back()->has_transparent_background = false;
-        appendQuadsToFillScreen(frame.renderPasses.back(),
m_rootLayerImpl.get(), m_backgroundColor, occlusionTracker);
+        appendQuadsToFillScreen(frame.renderPasses.back(), rootLayer(),
m_backgroundColor, occlusionTracker);
     }
 
     if (drawFrame)
@@ -627,9 +626,9 @@ gfx::Size LayerTreeHostImpl::contentSize() const
 {
     // TODO(aelias): Hardcoding the first child here is weird. Think of
     // a cleaner way to get the contentBounds on the Impl side.
-    if (!m_rootScrollLayerImpl || m_rootScrollLayerImpl->children().isEmpty())
+    if (!rootScrollLayer() || rootScrollLayer()->children().isEmpty())
         return gfx::Size();
-    return m_rootScrollLayerImpl->children()[0]->contentBounds();
+    return rootScrollLayer()->children()[0]->contentBounds();
 }
 
 static inline RenderPass* findRenderPassById(RenderPass::Id renderPassId, const
LayerTreeHostImpl::FrameData& frame)
@@ -816,6 +815,11 @@ void LayerTreeHostImpl::onVSyncParametersChanged(double
monotonicTimebase, doubl
     m_client->onVSyncParametersChanged(timebase, interval);
 }
 
+void LayerTreeHostImpl::OnCanDrawStateChangedForTree(LayerTreeImpl*)
+{
+  m_client->onCanDrawStateChanged(canDraw());
+}
+
 void LayerTreeHostImpl::drawLayers(FrameData& frame)
 {
     TRACE_EVENT0("cc", "LayerTreeHostImpl::drawLayers");
@@ -828,12 +832,12 @@ void LayerTreeHostImpl::drawLayers(FrameData& frame)
     m_fpsCounter->markBeginningOfFrame(base::TimeTicks::Now());
 
     if (m_debugState.showHudRects())
-       
m_debugRectHistory->saveDebugRectsForCurrentFrame(m_rootLayerImpl.get(),
*frame.renderSurfaceLayerList, frame.occludingScreenSpaceRects,
frame.nonOccludingScreenSpaceRects, m_debugState);
+        m_debugRectHistory->saveDebugRectsForCurrentFrame(rootLayer(),
*frame.renderSurfaceLayerList, frame.occludingScreenSpaceRects,
frame.nonOccludingScreenSpaceRects, m_debugState);
 
     // Because the contents of the HUD depend on everything else in the frame,
the contents
     // of its texture are updated as the last thing before the frame is drawn.
-    if (m_hudLayerImpl)
-        m_hudLayerImpl->updateHudTexture(m_resourceProvider.get());
+    if (m_activeTree->hud_layer())
+        m_activeTree->hud_layer()->updateHudTexture(m_resourceProvider.get());
 
     m_renderer->drawFrame(frame.renderPasses, frame.renderPassesById);
 
@@ -844,7 +848,7 @@ void LayerTreeHostImpl::drawLayers(FrameData& frame)
     // The next frame should start by assuming nothing has changed, and changes
are noted as they occur.
     for (unsigned int i = 0; i < frame.renderSurfaceLayerList->size(); i++)
        
(*frame.renderSurfaceLayerList)[i]->renderSurface()->damageTracker()->didDrawDamagedArea();
-    m_rootLayerImpl->resetAllChangeTrackingForSubtree();
+    rootLayer()->resetAllChangeTrackingForSubtree();
 }
 
 void LayerTreeHostImpl::didDrawAllLayers(const FrameData& frame)
@@ -907,23 +911,6 @@ void LayerTreeHostImpl::readback(void* pixels, const
gfx::Rect& rect)
     m_renderer->getFramebufferPixels(pixels, rect);
 }
 
-static LayerImpl* findRootScrollLayer(LayerImpl* layer)
-{
-    if (!layer)
-        return 0;
-
-    if (layer->scrollable())
-        return layer;
-
-    for (size_t i = 0; i < layer->children().size(); ++i) {
-        LayerImpl* found = findRootScrollLayer(layer->children()[i]);
-        if (found)
-            return found;
-    }
-
-    return 0;
-}
-
 // Content layers can be either directly scrollable or contained in an outer
 // scrolling layer which applies the scroll transform. Given a content layer,
 // this function returns the associated scroll layer if any.
@@ -943,26 +930,14 @@ static LayerImpl*
findScrollLayerForContentLayer(LayerImpl* layerImpl)
 
 void LayerTreeHostImpl::setRootLayer(scoped_ptr<LayerImpl> layer)
 {
-    m_rootLayerImpl = layer.Pass();
-    m_rootScrollLayerImpl = findRootScrollLayer(m_rootLayerImpl.get());
-    m_currentlyScrollingLayerImpl = 0;
-
-    if (m_rootLayerImpl && m_scrollingLayerIdFromPreviousTree != -1)
-        m_currentlyScrollingLayerImpl =
LayerTreeHostCommon::findLayerInSubtree(m_rootLayerImpl.get(),
m_scrollingLayerIdFromPrevio…
(message too large)

[commit-bot: I haz the power, 2012-12-06 18:24:27]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/nduca@chromium.org/11450015/16001

[nduca, 2012-12-06 18:40:19]

Yeah, when I move things completely over to the LTI, we'll have to figure out
how to do it. We may keep setRootLayer as a helper function...

[commit-bot: I haz the power, 2012-12-06 21:27:30]

Change committed as 171593