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

headless/public/util/dom_tree_extractor.cc

-// Copyright 2016 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.
-
-#include "headless/public/util/dom_tree_extractor.h"
-
-#include "base/bind.h"
-#include "base/json/json_writer.h"
-#include "headless/public/headless_devtools_client.h"
-
-namespace headless {
-
-DomTreeExtractor::DomTreeExtractor(HeadlessDevToolsClient* devtools_client)
-    : work_in_progress_(false),
-      devtools_client_(devtools_client),
-      weak_factory_(this) {}
-
-DomTreeExtractor::~DomTreeExtractor() {}
-
-void DomTreeExtractor::ExtractDomTree(
-    const std::vector<std::string>& css_style_whitelist,
-    DomResultCB callback) {
-  DCHECK(!work_in_progress_);
-  work_in_progress_ = true;
-
-  callback_ = std::move(callback);
-
-  devtools_client_->GetDOM()->GetDocument(
-      dom::GetDocumentParams::Builder().SetDepth(-1).SetPierce(true).Build(),
-      base::Bind(&DomTreeExtractor::OnDocumentFetched,
-                 weak_factory_.GetWeakPtr()));
-
-  devtools_client_->GetCSS()->GetExperimental()->GetLayoutTreeAndStyles(
-      css::GetLayoutTreeAndStylesParams::Builder()
-          .SetComputedStyleWhitelist(css_style_whitelist)
-          .Build(),
-      base::Bind(&DomTreeExtractor::OnLayoutTreeAndStylesFetched,
-                 weak_factory_.GetWeakPtr()));
-}
-
-void DomTreeExtractor::OnDocumentFetched(
-    std::unique_ptr<dom::GetDocumentResult> result) {
-  dom_tree_.document_result_ = std::move(result);
-  MaybeExtractDomTree();
-}
-
-void DomTreeExtractor::OnLayoutTreeAndStylesFetched(
-    std::unique_ptr<css::GetLayoutTreeAndStylesResult> result) {
-  dom_tree_.layout_tree_and_styles_result_ = std::move(result);
-  MaybeExtractDomTree();
-}
-
-void DomTreeExtractor::MaybeExtractDomTree() {
-  if (dom_tree_.document_result_ && dom_tree_.layout_tree_and_styles_result_) {
-    EnumerateNodes(dom_tree_.document_result_->GetRoot());
-    ExtractLayoutTreeNodes();
-    ExtractComputedStyles();
-
-    work_in_progress_ = false;
-
-    callback_.Run(std::move(dom_tree_));
-  }
-}
-
-void DomTreeExtractor::EnumerateNodes(const dom::Node* node) {
-  // Allocate an index and record the node pointer.
-  size_t index = dom_tree_.node_id_to_index_.size();
-  dom_tree_.node_id_to_index_[node->GetNodeId()] = index;
-  dom_tree_.dom_nodes_.push_back(node);
-
-  if (node->HasContentDocument())
-    EnumerateNodes(node->GetContentDocument());
-
-  if (node->HasChildren()) {
-    for (const std::unique_ptr<dom::Node>& child : *node->GetChildren()) {
-      EnumerateNodes(child.get());
-    }
-  }
-}
-
-void DomTreeExtractor::ExtractLayoutTreeNodes() {
-  dom_tree_.layout_tree_nodes_.reserve(
-      dom_tree_.layout_tree_and_styles_result_->GetLayoutTreeNodes()->size());
-
-  for (const std::unique_ptr<css::LayoutTreeNode>& layout_node :
-       *dom_tree_.layout_tree_and_styles_result_->GetLayoutTreeNodes()) {
-    std::unordered_map<NodeId, size_t>::const_iterator it =
-        dom_tree_.node_id_to_index_.find(layout_node->GetNodeId());
-    DCHECK(it != dom_tree_.node_id_to_index_.end());
-    dom_tree_.layout_tree_nodes_.push_back(layout_node.get());
-  }
-}
-
-void DomTreeExtractor::ExtractComputedStyles() {
-  dom_tree_.computed_styles_.reserve(
-      dom_tree_.layout_tree_and_styles_result_->GetComputedStyles()->size());
-
-  for (const std::unique_ptr<css::ComputedStyle>& computed_style :
-       *dom_tree_.layout_tree_and_styles_result_->GetComputedStyles()) {
-    dom_tree_.computed_styles_.push_back(computed_style.get());
-  }
-}
-
-DomTreeExtractor::DomTree::DomTree() {}
-DomTreeExtractor::DomTree::~DomTree() {}
-
-DomTreeExtractor::DomTree::DomTree(DomTree&& other) = default;
-
-}  // namespace headless