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

headless/public/util/flat_dom_tree_extractor.cc

Index: headless/public/util/flat_dom_tree_extractor.cc
diff --git a/headless/public/util/flat_dom_tree_extractor.cc b/headless/public/util/flat_dom_tree_extractor.cc
index 1ac9210aabc618e3711f7e57df61a034db828180..cc420ee20c43f2dde02ed096c6e451e234ad2d6c 100644
--- a/headless/public/util/flat_dom_tree_extractor.cc
+++ b/headless/public/util/flat_dom_tree_extractor.cc
@@ -26,49 +26,34 @@ void FlatDomTreeExtractor::ExtractDomTree(
 
   callback_ = std::move(callback);
 
+  // GetDocumentSnapshot requires DOM domain to be enabled.
   devtools_client_->GetDOM()->Enable();
-  devtools_client_->GetDOM()->GetFlattenedDocument(
-      dom::GetFlattenedDocumentParams::Builder()
-          .SetDepth(-1)
-          .SetPierce(true)
-          .Build(),
-      base::Bind(&FlatDomTreeExtractor::OnDocumentFetched,
-                 weak_factory_.GetWeakPtr()));
 
-  devtools_client_->GetCSS()->GetExperimental()->GetLayoutTreeAndStyles(
-      css::GetLayoutTreeAndStylesParams::Builder()
+  devtools_client_->GetCSS()->GetExperimental()->GetDocumentSnapshot(
+      css::GetDocumentSnapshotParams::Builder()
           .SetComputedStyleWhitelist(css_style_whitelist)
+          .SetDomDepth(-1)
+          .SetPierce(true)
           .Build(),
-      base::Bind(&FlatDomTreeExtractor::OnLayoutTreeAndStylesFetched,
+      base::Bind(&FlatDomTreeExtractor::OnDocumentSnapshotResult,
                  weak_factory_.GetWeakPtr()));
 }
 
-void FlatDomTreeExtractor::OnDocumentFetched(
-    std::unique_ptr<dom::GetFlattenedDocumentResult> result) {
-  dom_tree_.document_result_ = std::move(result);
-  MaybeExtractDomTree();
-}
+void FlatDomTreeExtractor::OnDocumentSnapshotResult(
+    std::unique_ptr<css::GetDocumentSnapshotResult> result) {
+  dom_tree_.document_snapshot_result_ = std::move(result);
 
-void FlatDomTreeExtractor::OnLayoutTreeAndStylesFetched(
-    std::unique_ptr<css::GetLayoutTreeAndStylesResult> result) {
-  dom_tree_.layout_tree_and_styles_result_ = std::move(result);
-  MaybeExtractDomTree();
-}
-
-void FlatDomTreeExtractor::MaybeExtractDomTree() {
-  if (dom_tree_.document_result_ && dom_tree_.layout_tree_and_styles_result_) {
-    for (const std::unique_ptr<headless::dom::Node>& node :
-         *dom_tree_.document_result_->GetNodes()) {
-      EnumerateNodes(node.get());
-    }
-    ExtractLayoutTreeNodes();
-    ExtractComputedStyles();
-    devtools_client_->GetDOM()->Disable();
+  for (const std::unique_ptr<headless::dom::Node>& node :
+       *dom_tree_.document_snapshot_result_->GetDomNodes()) {
+    EnumerateNodes(node.get());
+  }
+  ExtractLayoutTreeNodes();
+  ExtractComputedStyles();
+  devtools_client_->GetDOM()->Disable();
 
-    work_in_progress_ = false;
+  work_in_progress_ = false;
 
-    callback_.Run(std::move(dom_tree_));
-  }
+  callback_.Run(std::move(dom_tree_));
 }
 
 void FlatDomTreeExtractor::EnumerateNodes(const dom::Node* node) {
@@ -85,10 +70,10 @@ void FlatDomTreeExtractor::EnumerateNodes(const dom::Node* node) {
 
 void FlatDomTreeExtractor::ExtractLayoutTreeNodes() {
   dom_tree_.layout_tree_nodes_.reserve(
-      dom_tree_.layout_tree_and_styles_result_->GetLayoutTreeNodes()->size());
+      dom_tree_.document_snapshot_result_->GetLayoutTreeNodes()->size());
 
   for (const std::unique_ptr<css::LayoutTreeNode>& layout_node :
-       *dom_tree_.layout_tree_and_styles_result_->GetLayoutTreeNodes()) {
+       *dom_tree_.document_snapshot_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());
@@ -98,10 +83,10 @@ void FlatDomTreeExtractor::ExtractLayoutTreeNodes() {
 
 void FlatDomTreeExtractor::ExtractComputedStyles() {
   dom_tree_.computed_styles_.reserve(
-      dom_tree_.layout_tree_and_styles_result_->GetComputedStyles()->size());
+      dom_tree_.document_snapshot_result_->GetComputedStyles()->size());
 
   for (const std::unique_ptr<css::ComputedStyle>& computed_style :
-       *dom_tree_.layout_tree_and_styles_result_->GetComputedStyles()) {
+       *dom_tree_.document_snapshot_result_->GetComputedStyles()) {
     dom_tree_.computed_styles_.push_back(computed_style.get());
   }
 }