[Invalidation Tracking] Add trace events for compositor based invalidations

Source/core/rendering/compositing/GraphicsLayerUpdater.cpp

 /*
  * Copyright (C) 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2014 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 10 matching lines @@
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "config.h"
 #include "core/rendering/compositing/GraphicsLayerUpdater.h"
 
 #include "core/html/HTMLMediaElement.h"
+#include "core/inspector/InspectorTraceEvents.h"
 #include "core/rendering/RenderLayer.h"
 #include "core/rendering/RenderLayerReflectionInfo.h"
 #include "core/rendering/RenderPart.h"
 #include "core/rendering/compositing/CompositedLayerMapping.h"
 #include "core/rendering/compositing/RenderLayerCompositor.h"
 #include "platform/TraceEvent.h"
 
 namespace blink {
 
 class GraphicsLayerUpdater::UpdateContext {
@@ skipping 33 matching lines @@
 
 GraphicsLayerUpdater::GraphicsLayerUpdater()
     : m_needsRebuildTree(false)
 {
 }
 
 GraphicsLayerUpdater::~GraphicsLayerUpdater()
 {
 }
 
-void GraphicsLayerUpdater::update(RenderLayer& layer, Vector<RenderLayer*>& layersNeedingPaintInvalidation)
+void GraphicsLayerUpdater::update(RenderLayer& layer, LayersNeedingPaintInvalidation& layersNeedingPaintInvalidation)
 {
     TRACE_EVENT0("blink", "GraphicsLayerUpdater::update");
     updateRecursive(layer, DoNotForceUpdate, UpdateContext(), layersNeedingPaintInvalidation);
     layer.compositor()->updateRootLayerPosition();
 }
 
-void GraphicsLayerUpdater::updateRecursive(RenderLayer& layer, UpdateType updateType, const UpdateContext& context, Vector<RenderLayer*>& layersNeedingPaintInvalidation)
+void GraphicsLayerUpdater::updateRecursive(RenderLayer& layer, UpdateType updateType, const UpdateContext& context, LayersNeedingPaintInvalidation& layersNeedingPaintInvalidation)
 {
     if (layer.hasCompositedLayerMapping()) {
         CompositedLayerMapping* mapping = layer.compositedLayerMapping();
 
         if (updateType == ForceUpdate || mapping->needsGraphicsLayerUpdate()) {
             const RenderLayer* compositingContainer = context.compositingContainer(layer);
             ASSERT(compositingContainer == layer.enclosingLayerWithCompositedLayerMapping(ExcludeSelf));
 
             if (mapping->updateRequiresOwnBackingStoreForAncestorReasons(compositingContainer)) {
-                layersNeedingPaintInvalidation.append(&layer);
+                layersNeedingPaintInvalidation.append(std::make_pair(&layer, InspectorLayerInvalidationTrackingEvent::AncestorRequiresNewLayer));

[pdr., 2014/09/12 04:07:17]

Why do we need to track the {layer,reason} pair together? Could we just issue
the trace event here instead?

[kouhei (in TOK), 2014/09/12 05:02:12]

The string is put into vector to avoid code duplication.
It was originally written in that way (Patch Set #1), but the 5 lines are mostly
copy&paste as chrishtr@ pointed out.

                 updateType = ForceUpdate;
             }
 
             if (mapping->updateGraphicsLayerConfiguration())
                 m_needsRebuildTree = true;
 
             mapping->updateGraphicsLayerGeometry(compositingContainer, context.compositingStackingContext(), layersNeedingPaintInvalidation);
 
             if (mapping->hasUnpositionedOverflowControlsLayers())
                 layer.scrollableArea()->positionOverflowControls(IntSize());
@@ skipping 15 matching lines @@
     if (layer.hasCompositedLayerMapping())
         layer.compositedLayerMapping()->assertNeedsToUpdateGraphicsLayerBitsCleared();
 
     for (RenderLayer* child = layer.firstChild(); child; child = child->nextSibling())
         assertNeedsToUpdateGraphicsLayerBitsCleared(*child);
 }
 
 #endif
 
 } // namespace blink