Add optional debugging output of what paint chunks go into what layers.

BUG=668342
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Review-Url: https://codereview.chromium.org/2577123002
Cr-Commit-Position: refs/heads/master@{#439151}

third_party/WebKit/Source/core/frame/FrameView.cpp

@@ -3058,7 +3058,8 @@ void FrameView::pushPaintArtifactToCompositor() {
 
   m_paintArtifactCompositor->update(
       m_paintController->paintArtifact(),
-      m_paintController->paintChunksRasterInvalidationTrackingMap());
+      m_paintController->paintChunksRasterInvalidationTrackingMap(),
+      m_isStoringCompositedLayerDebugInfo);
 }
 
 std::unique_ptr<JSONObject> FrameView::compositedLayersAsJSON(

third_party/WebKit/Source/core/frame/FrameView.h

@@ -358,6 +358,10 @@ class CORE_EXPORT FrameView final
 
   static void setInitialTracksPaintInvalidationsForTesting(bool);
 
+  void setIsStoringCompositedLayerDebugInfo(bool val) {
+    m_isStoringCompositedLayerDebugInfo = val;
+  }
+
   // These methods are for testing.
   void setTracksPaintInvalidations(bool);
   bool isTrackingPaintInvalidations() const {
@@ -1146,6 +1150,7 @@ class CORE_EXPORT FrameView final
   // For Slimming Paint v2 only.
   std::unique_ptr<PaintController> m_paintController;
   std::unique_ptr<PaintArtifactCompositor> m_paintArtifactCompositor;
+  bool m_isStoringCompositedLayerDebugInfo;
 };
 
 inline void FrameView::incrementVisuallyNonEmptyCharacterCount(unsigned count) {

third_party/WebKit/Source/core/testing/Internals.h

@@ -385,6 +385,9 @@ class Internals final : public GarbageCollected<Internals>,
 
   Vector<String> getReferencedFilePaths() const;
 
+  void startStoringCompositedLayerDebugInfo(Document*, ExceptionState&);
+  void stopStoringCompositedLayerDebugInfo(Document*, ExceptionState&);
+
   void startTrackingRepaints(Document*, ExceptionState&);
   void stopTrackingRepaints(Document*, ExceptionState&);
   void updateLayoutIgnorePendingStylesheetsAndRunPostLayoutTasks(

third_party/WebKit/Source/core/testing/Internals.idl

@@ -233,6 +233,9 @@
 
     sequence<DOMString> getReferencedFilePaths();
 
+    [RaisesException] void startStoringCompositedLayerDebugInfo(Document document);
+    [RaisesException] void stopStoringCompositedLayerDebugInfo(Document document);
+
     // These functions both reset the tracked repaint rects. They are intended to be used in the following order:
     //  startTrackingRepaints(), repaintRectsAsText(), stopTrackingRepaints().
     [RaisesException] void startTrackingRepaints(Document document);

third_party/WebKit/Source/platform/graphics/compositing/PaintArtifactCompositor.cpp

@@ -77,6 +77,11 @@ class PaintArtifactCompositor::ContentLayerClientImpl
   }
   void SetPaintableRegion(gfx::Rect region) { m_paintableRegion = region; }
 
+  void addPaintChunkDebugData(std::unique_ptr<JSONArray> json) {
+    m_paintChunkDebugData.append(std::move(json));
+  }
+  void clearPaintChunkDebugData() { m_paintChunkDebugData.clear(); }
+
   // cc::ContentLayerClient
   gfx::Rect PaintableRegion() override { return m_paintableRegion; }
   scoped_refptr<cc::DisplayItemList> PaintContentsToDisplayList(
@@ -130,7 +135,7 @@ class PaintArtifactCompositor::ContentLayerClientImpl
     }
   }
 
-  std::unique_ptr<JSONObject> layerAsJSON() {
+  std::unique_ptr<JSONObject> layerAsJSON(LayerTreeFlags flags) {
     std::unique_ptr<JSONObject> json = JSONObject::create();
     json->setString("name", m_debugName);
     IntSize bounds(m_ccPictureLayer->bounds().width(),
@@ -140,6 +145,14 @@ class PaintArtifactCompositor::ContentLayerClientImpl
     json->setBoolean("contentsOpaque", m_ccPictureLayer->contents_opaque());
     json->setBoolean("drawsContent", m_ccPictureLayer->DrawsContent());
 
+    if (flags & LayerTreeIncludesDebugInfo) {
+      std::unique_ptr<JSONArray> paintChunkContentsArray = JSONArray::create();
+      for (const auto& debugData : m_paintChunkDebugData) {
+        paintChunkContentsArray->pushValue(debugData->clone());
+      }
+      json->setArray("paintChunkContents", std::move(paintChunkContentsArray));
+    }
+
     ccLayersRasterInvalidationTrackingMap().asJSON(m_ccPictureLayer.get(),
                                                    json.get());
     return json;
@@ -157,6 +170,7 @@ class PaintArtifactCompositor::ContentLayerClientImpl
   scoped_refptr<cc::PictureLayer> m_ccPictureLayer;
   scoped_refptr<cc::DisplayItemList> m_ccDisplayItemList;
   gfx::Rect m_paintableRegion;
+  Vector<std::unique_ptr<JSONArray>> m_paintChunkDebugData;
 };
 
 PaintArtifactCompositor::PaintArtifactCompositor() {
@@ -193,7 +207,7 @@ std::unique_ptr<JSONObject> PaintArtifactCompositor::layersAsJSON(
     LayerTreeFlags flags) const {
   std::unique_ptr<JSONArray> layersJSON = JSONArray::create();
   for (const auto& client : m_contentLayerClients) {
-    layersJSON->pushObject(client->layerAsJSON());
+    layersJSON->pushObject(client->layerAsJSON(flags));
   }
   std::unique_ptr<JSONObject> json = JSONObject::create();
   json->setArray("layers", std::move(layersJSON));
@@ -301,7 +315,8 @@ scoped_refptr<cc::Layer> PaintArtifactCompositor::layerForPaintChunk(
     const PaintChunk& paintChunk,
     gfx::Vector2dF& layerOffset,
     Vector<std::unique_ptr<ContentLayerClientImpl>>& newContentLayerClients,
-    RasterInvalidationTracking* tracking) {
+    RasterInvalidationTracking* tracking,
+    bool storeDebugInfo) {
   DCHECK(paintChunk.size());
 
   // If the paint chunk is a foreign layer, just return that layer.
@@ -329,6 +344,16 @@ scoped_refptr<cc::Layer> PaintArtifactCompositor::layerForPaintChunk(
   DCHECK(!tracking ||
          tracking->trackedRasterInvalidations.size() ==
              paintChunk.rasterInvalidationRects.size());
+
+  contentLayerClient->clearPaintChunkDebugData();
+  if (storeDebugInfo) {
+    contentLayerClient->addPaintChunkDebugData(
+        paintArtifact.getDisplayItemList().subsequenceAsJSON(
+            paintChunk.beginIndex, paintChunk.endIndex,
+            DisplayItemList::SkipNonDrawings |
+                DisplayItemList::ShownOnlyDisplayItemTypes));
+  }
+
   for (unsigned index = 0; index < paintChunk.rasterInvalidationRects.size();
        ++index) {
     IntRect rect(enclosingIntRect(paintChunk.rasterInvalidationRects[index]));
@@ -768,7 +793,8 @@ void PropertyTreeManager::buildEffectNodesRecursively(
 
 void PaintArtifactCompositor::update(
     const PaintArtifact& paintArtifact,
-    RasterInvalidationTrackingMap<const PaintChunk>* rasterChunkInvalidations) {
+    RasterInvalidationTrackingMap<const PaintChunk>* rasterChunkInvalidations,
+    bool storeDebugInfo) {
   DCHECK(m_rootLayer);
 
   cc::LayerTree* layerTree = m_rootLayer->GetLayerTree();
@@ -794,7 +820,8 @@ void PaintArtifactCompositor::update(
     scoped_refptr<cc::Layer> layer = layerForPaintChunk(
         paintArtifact, paintChunk, layerOffset, newContentLayerClients,
         rasterChunkInvalidations ? rasterChunkInvalidations->find(&paintChunk)
-                                 : nullptr);
+                                 : nullptr,
+        storeDebugInfo);
 
     int transformId = propertyTreeManager.compositorIdForTransformNode(
         paintChunk.properties.propertyTreeState.transform());

third_party/WebKit/Source/platform/graphics/compositing/PaintArtifactCompositor.h

@@ -48,9 +48,13 @@ class PLATFORM_EXPORT PaintArtifactCompositor {
   }
 
   // Updates the layer tree to match the provided paint artifact.
+  // If |storeDebugInfo| is true, stores detailed debugging information in
+  // the layers that will be output as part of a call to layersAsJSON
+  // (if LayerTreeIncludesDebugInfo is specified).
   void update(
       const PaintArtifact&,
-      RasterInvalidationTrackingMap<const PaintChunk>* paintChunkInvalidations);
+      RasterInvalidationTrackingMap<const PaintChunk>* paintChunkInvalidations,
+      bool storeDebugInfo);
 
   // The root layer of the tree managed by this object.
   cc::Layer* rootLayer() const { return m_rootLayer.get(); }
@@ -93,7 +97,8 @@ class PLATFORM_EXPORT PaintArtifactCompositor {
       const PaintChunk&,
       gfx::Vector2dF& layerOffset,
       Vector<std::unique_ptr<ContentLayerClientImpl>>& newContentLayerClients,
-      RasterInvalidationTracking*);
+      RasterInvalidationTracking*,
+      bool storeDebugInfo);
 
   // Finds a client among the current vector of clients that matches the paint
   // chunk's id, or otherwise allocates a new one.

third_party/WebKit/Source/platform/graphics/compositing/PaintArtifactCompositorTest.cpp

@@ -94,7 +94,7 @@ class PaintArtifactCompositorTestWithPropertyTrees : public ::testing::Test {
   }
 
   void update(const PaintArtifact& artifact) {
-    m_paintArtifactCompositor->update(artifact, nullptr);
+    m_paintArtifactCompositor->update(artifact, nullptr, false);
     m_webLayerTreeView->layerTreeHost()->LayoutAndUpdateLayers();
   }
 

third_party/WebKit/Source/platform/graphics/paint/DisplayItemList.cpp

@@ -66,7 +66,14 @@ std::unique_ptr<JSONArray> DisplayItemList::subsequenceAsJSON(
 #ifndef NDEBUG
     StringBuilder stringBuilder;
     displayItem.dumpPropertiesAsDebugString(stringBuilder);
+
+    if (options & ShownOnlyDisplayItemTypes) {
+      json->setString("type",
+                      DisplayItem::typeAsDebugString(displayItem.getType()));
+    } else {
       json->setString("properties", stringBuilder.toString());
+    }
+
 #endif
     if (displayItem.hasValidClient()) {
 #if CHECK_DISPLAY_ITEM_CLIENT_ALIVENESS
@@ -77,12 +84,10 @@ std::unique_ptr<JSONArray> DisplayItemList::subsequenceAsJSON(
 
       if (options & ShowClientDebugName) {
 #endif
-#ifdef NDEBUG
         json->setString(
             "clientDebugName",
             String::format("clientDebugName: \"%s\"",
                            displayItem.client().debugName().ascii().data()));
-#endif
       }
 #ifndef NDEBUG
       if ((options & ShowPictures) && displayItem.isDrawing()) {

third_party/WebKit/Source/platform/graphics/paint/DisplayItemList.h

@@ -72,8 +72,9 @@ class PLATFORM_EXPORT DisplayItemList
   enum JsonOptions {
     Default = 0,
     ShowPictures = 1,
-    SkipNonDrawings = 2,
-    ShowClientDebugName = 4,
+    SkipNonDrawings = 1 << 1,
+    ShowClientDebugName = 1 << 2,
+    ShownOnlyDisplayItemTypes = 1 << 3
   };
   typedef unsigned JsonFlags;