Add stacking context information to InspectorDOMSnapshot.

R=pfeldman@chromium.org

Change-Id: Ib16d60ee5ec23b7e6ac1e7b5f657651beeeb7168
Reviewed-on: https://chromium-review.googlesource.com/1142520
Commit-Queue: Jandro Alderman <aalderman@chromium.org>
Reviewed-by: Andrey Kosyakov <caseq@chromium.org>
Reviewed-by: Pavel Feldman <pfeldman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#584861}

third_party/WebKit/LayoutTests/inspector-protocol/dom-snapshot/dom-snapshot-getSnapshot-expected.txt

@@ -750,7 +750,8 @@ Tests DOMSnapshot.getSnapshot method.
         "y": 0,
         "width": 800,
         "height": 600
-      }
+      },
+      "isStackingContext": true
     },
     {
       "domNodeIndex": 1,
@@ -760,7 +761,8 @@ Tests DOMSnapshot.getSnapshot method.
         "width": 785,
         "height": 1135
       },
-      "styleIndex": 0
+      "styleIndex": 0,
+      "isStackingContext": true
     },
     {
       "domNodeIndex": 9,
@@ -1295,7 +1297,8 @@ Tests DOMSnapshot.getSnapshot method.
         "width": 32,
         "height": 200
       },
-      "styleIndex": 11
+      "styleIndex": 11,
+      "isStackingContext": true
     },
     {
       "domNodeIndex": 33,
@@ -1328,7 +1331,8 @@ Tests DOMSnapshot.getSnapshot method.
           "numCharacters": 5
         }
       ],
-      "styleIndex": 12
+      "styleIndex": 12,
+      "isStackingContext": true
     },
     {
       "domNodeIndex": 35,
@@ -1347,7 +1351,8 @@ Tests DOMSnapshot.getSnapshot method.
         "y": 0,
         "width": 400,
         "height": 200
-      }
+      },
+      "isStackingContext": true
     },
     {
       "domNodeIndex": 37,
@@ -1357,7 +1362,8 @@ Tests DOMSnapshot.getSnapshot method.
         "width": 400,
         "height": 200
       },
-      "styleIndex": 14
+      "styleIndex": 14,
+      "isStackingContext": true
     },
     {
       "domNodeIndex": 44,

third_party/WebKit/LayoutTests/inspector-protocol/dom-snapshot/dom-snapshot-getSnapshot-pseudo-element-expected.txt

@@ -248,7 +248,8 @@ Tests DOMSnapshot.getSnapshot exports layout tree nodes associated with pseudo e
         "y": 0,
         "width": 800,
         "height": 600
-      }
+      },
+      "isStackingContext": true
     },
     {
       "domNodeIndex": 1,
@@ -258,7 +259,8 @@ Tests DOMSnapshot.getSnapshot exports layout tree nodes associated with pseudo e
         "width": 800,
         "height": 600
       },
-      "styleIndex": 0
+      "styleIndex": 0,
+      "isStackingContext": true
     },
     {
       "domNodeIndex": 8,
@@ -278,7 +280,8 @@ Tests DOMSnapshot.getSnapshot exports layout tree nodes associated with pseudo e
         "width": 200,
         "height": 200
       },
-      "styleIndex": 0
+      "styleIndex": 0,
+      "isStackingContext": true
     },
     {
       "domNodeIndex": 11,
@@ -344,7 +347,8 @@ Tests DOMSnapshot.getSnapshot exports layout tree nodes associated with pseudo e
           "numCharacters": 7
         }
       ],
-      "styleIndex": 0
+      "styleIndex": 0,
+      "isStackingContext": true
     },
     {
       "domNodeIndex": 14,
@@ -354,7 +358,8 @@ Tests DOMSnapshot.getSnapshot exports layout tree nodes associated with pseudo e
         "width": 200,
         "height": 200
       },
-      "styleIndex": 0
+      "styleIndex": 0,
+      "isStackingContext": true
     },
     {
       "domNodeIndex": 15,
@@ -450,7 +455,8 @@ Tests DOMSnapshot.getSnapshot exports layout tree nodes associated with pseudo e
         "width": 200,
         "height": 200
       },
-      "styleIndex": 0
+      "styleIndex": 0,
+      "isStackingContext": true
     },
     {
       "domNodeIndex": 20,
@@ -615,7 +621,8 @@ Tests DOMSnapshot.getSnapshot exports layout tree nodes associated with pseudo e
           "numCharacters": 13
         }
       ],
-      "styleIndex": 0
+      "styleIndex": 0,
+      "isStackingContext": true
     }
   ],
   "computedStyles": [

third_party/WebKit/LayoutTests/inspector-protocol/dom-snapshot/dom-snapshot-getSnapshot-viewport-expected.txt

@@ -189,7 +189,8 @@ Emulating device: 600x600x1
         "y": 0,
         "width": 300,
         "height": 300
-      }
+      },
+      "isStackingContext": true
     },
     {
       "domNodeIndex": 3,
@@ -198,7 +199,8 @@ Emulating device: 600x600x1
         "y": 0,
         "width": 300,
         "height": 0
-      }
+      },
+      "isStackingContext": true
     },
     {
       "domNodeIndex": 15,
@@ -216,7 +218,8 @@ Emulating device: 600x600x1
         "y": 100,
         "width": 100,
         "height": 100
-      }
+      },
+      "isStackingContext": true
     },
     {
       "domNodeIndex": 17,
@@ -238,7 +241,8 @@ Emulating device: 600x600x1
           "startCharacterIndex": 0,
           "numCharacters": 6
         }
-      ]
+      ],
+      "isStackingContext": true
     }
   ],
   "computedStyles": []

third_party/blink/renderer/core/inspector/browser_protocol.pdl

@@ -2076,6 +2076,8 @@ experimental domain DOMSnapshot
       # that are painted together will have the same index. Only provided if includePaintOrder in
       # getSnapshot was true.
       optional integer paintOrder
+      # Set to true to indicate the element begins a new stacking context.
+      optional boolean isStackingContext
 
   # A subset of the full ComputedStyle as defined by the request whitelist.
   type ComputedStyle extends object
@@ -2185,6 +2187,8 @@ experimental domain DOMSnapshot
       array of Rectangle bounds
       # Contents of the LayoutText, if any.
       array of StringIndex text
+      # Stacking context information.
+      RareBooleanData stackingContexts
 
   # Details of post layout rendered text positions. The exact layout should not be regarded as
   # stable and may change between versions.

third_party/blink/renderer/core/inspector/inspector_dom_snapshot_agent.cc

@@ -540,6 +540,7 @@ void InspectorDOMSnapshotAgent::VisitDocument2(Document* document) {
                   .setBounds(protocol::Array<protocol::Array<double>>::create())
                   .setText(protocol::Array<int>::create())
                   .setStyles(protocol::Array<protocol::Array<int>>::create())
+                  .setStackingContexts(BooleanData())
                   .build())
           .setTextBoxes(
               protocol::DOMSnapshot::TextBoxSnapshot::create()
@@ -813,6 +814,9 @@ int InspectorDOMSnapshotAgent::VisitLayoutTreeNode(LayoutObject* layout_object,
   if (style_index != -1)
     layout_tree_node->setStyleIndex(style_index);
 
+  if (layout_object->Style() && layout_object->Style()->IsStacked())
+    layout_tree_node->setIsStackingContext(true);
+
   if (paint_order_map_) {
     PaintLayer* paint_layer = layout_object->EnclosingLayer();
 
@@ -866,6 +870,9 @@ int InspectorDOMSnapshotAgent::BuildLayoutTreeNode(LayoutObject* layout_object,
   layout_tree_snapshot->getBounds()->addItem(BuildRectForFloatRect2(
       FloatRect(layout_object->AbsoluteBoundingBoxRect())));
 
+  if (layout_object->Style() && layout_object->Style()->IsStacked())
+    SetRare(layout_tree_snapshot->getStackingContexts(), layout_index);
+
   String text = layout_object->IsText() ? ToLayoutText(layout_object)->GetText()
                                         : String();
   layout_tree_snapshot->getText()->addItem(AddString(text));