DevTools: make DOM.getNodeForLocation work with disabled DOM domain.

Change-Id: Ie0cda615136c02d8e01a16d105cdcddf2dd0938f
Reviewed-on: https://chromium-review.googlesource.com/c/1258384
Commit-Queue: Pavel Feldman <pfeldman@chromium.org>
Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#596431}

third_party/WebKit/LayoutTests/inspector-protocol/dom/dom-getBoxModel.js

@@ -27,10 +27,14 @@
 
   var NodeTracker = await testRunner.loadScript('../resources/node-tracker.js');
   var nodeTracker = new NodeTracker(dp);
-  dp.DOM.enable();
-  await dp.DOM.getNodeForLocation({x: 100, y: 200});
-  await dp.DOM.getNodeForLocation({x: 250, y: 250});
-  await dp.DOM.getNodeForLocation({x: 500, y: 500});
+  const bn1 = (await dp.DOM.getNodeForLocation({x: 100, y: 200})).result.backendNodeId;
+  const bn2 = (await dp.DOM.getNodeForLocation({x: 250, y: 250})).result.backendNodeId;
+  const bn3 = (await dp.DOM.getNodeForLocation({x: 500, y: 500})).result.backendNodeId;
+
+  await dp.DOM.enable();
+  await nodeTracker.nodeForBackendId(bn1);
+  await nodeTracker.nodeForBackendId(bn2);
+  await nodeTracker.nodeForBackendId(bn3);
 
   for (var nodeId of nodeTracker.nodeIds()) {
     var node = nodeTracker.nodeForId(nodeId);

third_party/WebKit/LayoutTests/inspector-protocol/dom/dom-getNodeForLocation-skip-shadow.js

@@ -8,9 +8,9 @@
   var NodeTracker = await testRunner.loadScript('../resources/node-tracker.js');
   var nodeTracker = new NodeTracker(dp);
 
-  dp.DOM.enable();
   var message = await dp.DOM.getNodeForLocation({x: 10, y: 10, includeUserAgentShadowDOM: false});
-  var nodeId = message.result.nodeId;
-  testRunner.log(nodeTracker.nodeForId(nodeId), 'Node: ');
+  var backendNodeId = message.result.backendNodeId;
+  await dp.DOM.enable();
+  testRunner.log(await nodeTracker.nodeForBackendId(backendNodeId), 'Node: ');
   testRunner.completeTest();
 })

third_party/WebKit/LayoutTests/inspector-protocol/dom/dom-getNodeForLocation.js

@@ -5,10 +5,10 @@
   var NodeTracker = await testRunner.loadScript('../resources/node-tracker.js');
   var nodeTracker = new NodeTracker(dp);
 
-  dp.DOM.enable();
   var response = await dp.DOM.getNodeForLocation({x: 10, y: 10});
-  var nodeId = response.result.nodeId;
-  testRunner.log(nodeTracker.nodeForId(nodeId), 'Node: ');
+  var backendNodeId = response.result.backendNodeId;
+  await dp.DOM.enable();
+  testRunner.log(await nodeTracker.nodeForBackendId(backendNodeId), 'Node: ');
   testRunner.completeTest();
 })
 

third_party/WebKit/LayoutTests/inspector-protocol/resources/node-tracker.js

 (class NodeTracker {
   constructor(dp) {
     this._nodes = new Map();
+    this._dp = dp;
     dp.DOM.onSetChildNodes(message => message.params.nodes.forEach(node => this._addNode(node)));
   }
 
@@ -18,6 +19,13 @@
     return this._nodes.get(nodeId) || null;
   }
 
+  async nodeForBackendId(backendNodeId) {
+    const response = await this._dp.DOM.pushNodesByBackendIdsToFrontend({backendNodeIds: [backendNodeId]});
+    if (!response.result)
+      throw new Error(JSON.stringify(response));
+    return this.nodeForId(response.result.nodeIds[0]);
+  }
+
   nodes() {
     return Array.from(this._nodes.values());
   }

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

@@ -1530,7 +1530,8 @@ domain DOM
       # Resulting node.
       array of Node nodes
 
-  # Returns node id at given location.
+  # Returns node id at given location. Depending on whether DOM domain is enabled, nodeId is
+  # either returned or not.
   experimental command getNodeForLocation
     parameters
       # X coordinate.
@@ -1540,8 +1541,10 @@ domain DOM
       # False to skip to the nearest non-UA shadow root ancestor (default: false).
       optional boolean includeUserAgentShadowDOM
     returns
-      # Id of the node at given coordinates.
-      NodeId nodeId
+      # Resulting node.
+      BackendNodeId backendNodeId
+      # Id of the node at given coordinates, only when enabled.
+      optional NodeId nodeId
 
   # Returns node's HTML markup.
   command getOuterHTML

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

@@ -1315,22 +1315,18 @@ Response InspectorDOMAgent::getNodeForLocation(
     int x,
     int y,
     Maybe<bool> optional_include_user_agent_shadow_dom,
-    int* node_id) {
-  if (!enabled_.Get())
-    return Response::Error("DOM agent is not enabled");
+    int* backend_node_id,
+    Maybe<int>* node_id) {
   bool include_user_agent_shadow_dom =
       optional_include_user_agent_shadow_dom.fromMaybe(false);
-  Response response = PushDocumentUponHandlelessOperation();
-  if (!response.isSuccess())
-    return response;
-
+  Document* document = inspected_frames_->Root()->GetDocument();
   LayoutPoint document_point(x * inspected_frames_->Root()->PageZoomFactor(),
                              y * inspected_frames_->Root()->PageZoomFactor());
   HitTestRequest request(HitTestRequest::kMove | HitTestRequest::kReadOnly |
                          HitTestRequest::kAllowChildFrameContent);
-  HitTestLocation location(document_->View()->DocumentToFrame(document_point));
+  HitTestLocation location(document->View()->DocumentToFrame(document_point));
   HitTestResult result(request, location);
-  document_->GetFrame()->ContentLayoutObject()->HitTest(location, result);
+  document->GetFrame()->ContentLayoutObject()->HitTest(location, result);
   if (!include_user_agent_shadow_dom)
     result.SetToShadowHostIfInRestrictedShadowRoot();
   Node* node = result.InnerPossiblyPseudoNode();
@@ -1338,7 +1334,13 @@ Response InspectorDOMAgent::getNodeForLocation(
     node = node->parentNode();
   if (!node)
     return Response::Error("No node found at given location");
-  *node_id = PushNodePathToFrontend(node);
+  *backend_node_id = DOMNodeIds::IdForNode(node);
+  if (enabled_.Get()) {
+    Response response = PushDocumentUponHandlelessOperation();
+    if (!response.isSuccess())
+      return response;
+    *node_id = PushNodePathToFrontend(node);
+  }
   return Response::OK();
 }
 
@@ -2143,6 +2145,11 @@ Response InspectorDOMAgent::pushNodesByBackendIdsToFrontend(
     std::unique_ptr<protocol::Array<int>>* result) {
   if (!enabled_.Get())
     return Response::Error("DOM agent is not enabled");
+
+  Response response = PushDocumentUponHandlelessOperation();
+  if (!response.isSuccess())
+    return response;
+
   *result = protocol::Array<int>::create();
   for (size_t index = 0; index < backend_node_ids->length(); ++index) {
     Node* node = DOMNodeIds::NodeForId(backend_node_ids->get(index));

third_party/blink/renderer/core/inspector/inspector_dom_agent.h

@@ -200,7 +200,8 @@ class CORE_EXPORT InspectorDOMAgent final
       int x,
       int y,
       protocol::Maybe<bool> include_user_agent_shadow_dom,
-      int* out_node_id) override;
+      int* backend_node_id,
+      protocol::Maybe<int>* node_id) override;
   protocol::Response getRelayoutBoundary(int node_id,
                                          int* out_node_id) override;
   protocol::Response describeNode(