[devtools] Add DOMSnapshot domain for dom+layout+style snapshots.

headless/public/util/flat_dom_tree_extractor.h

 // Copyright 2017 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.
 
 #ifndef HEADLESS_PUBLIC_UTIL_DOM_TREE_EXTRACTOR_H_
 #define HEADLESS_PUBLIC_UTIL_DOM_TREE_EXTRACTOR_H_
 
 #include <unordered_map>
 #include <vector>
 
@@ skipping 29 matching lines @@
     // Map of node IDs to indexes into |dom_nodes_|.
     std::unordered_map<NodeId, Index> node_id_to_index_;
 
     std::vector<const css::LayoutTreeNode*> layout_tree_nodes_;
 
     std::vector<const css::ComputedStyle*> computed_styles_;
 
    private:
     friend class FlatDomTreeExtractor;
 
-    // Owns the raw pointers in |dom_nodes_|.
-    std::unique_ptr<dom::GetFlattenedDocumentResult> document_result_;
-
-    // Owns the raw pointers in |layout_tree_nodes_|.
-    std::unique_ptr<css::GetLayoutTreeAndStylesResult>
-        layout_tree_and_styles_result_;
+    // Owns the raw pointers in |dom_nodes_| and |layout_tree_nodes_|.
+    std::unique_ptr<css::GetDocumentSnapshotResult> document_snapshot_result_;
 
     DISALLOW_COPY_AND_ASSIGN(DomTree);
   };
 
   using DomResultCB = base::Callback<void(DomTree)>;
 
   // Extracts all nodes from the DOM.  This is an asynchronous operation and
   // it's an error to call ExtractDom while a previous operation is in flight.
   void ExtractDomTree(const std::vector<std::string>& css_style_whitelist,
                       DomResultCB callback);
 
  private:
-  void OnDocumentFetched(
-      std::unique_ptr<dom::GetFlattenedDocumentResult> result);
+  void OnDocumentSnapshotResult(
+      std::unique_ptr<css::GetDocumentSnapshotResult> result);
 
-  void OnLayoutTreeAndStylesFetched(
-      std::unique_ptr<css::GetLayoutTreeAndStylesResult> result);
-
-  void MaybeExtractDomTree();
   void EnumerateNodes(const dom::Node* node);
   void ExtractLayoutTreeNodes();
   void ExtractComputedStyles();
 
   DomResultCB callback_;
   DomTree dom_tree_;
   bool work_in_progress_;
   HeadlessDevToolsClient* devtools_client_;  // NOT OWNED
   base::WeakPtrFactory<FlatDomTreeExtractor> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(FlatDomTreeExtractor);
 };
 
 }  // namespace headless
 
 #endif  // HEADLESS_PUBLIC_UTIL_DOM_TREE_EXTRACTOR_H_