Add a DOM.getLayoutTreeNodes devtools command

third_party/WebKit/Source/core/inspector/InspectorDOMAgent.cpp

Index: third_party/WebKit/Source/core/inspector/InspectorDOMAgent.cpp
diff --git a/third_party/WebKit/Source/core/inspector/InspectorDOMAgent.cpp b/third_party/WebKit/Source/core/inspector/InspectorDOMAgent.cpp
index 57c3c68cf8e576bd11a7bb2bafce430175c4a91e..54d1faaea05b0e39848554cfbc80de5ba69c6d69 100644
--- a/third_party/WebKit/Source/core/inspector/InspectorDOMAgent.cpp
+++ b/third_party/WebKit/Source/core/inspector/InspectorDOMAgent.cpp
@@ -67,7 +67,9 @@
 #include "core/inspector/InspectorHistory.h"
 #include "core/inspector/V8InspectorString.h"
 #include "core/layout/HitTestResult.h"
+#include "core/layout/LayoutInline.h"
 #include "core/layout/api/LayoutViewItem.h"
+#include "core/layout/line/InlineTextBox.h"
 #include "core/loader/DocumentLoader.h"
 #include "core/page/FrameTree.h"
 #include "core/page/Page.h"
@@ -137,6 +139,16 @@ v8::Local<v8::Value> nodeV8Value(v8::Local<v8::Context> context, Node* node) {
   return toV8(node, context->Global(), isolate);
 }
 
+std::unique_ptr<protocol::DOM::Rect> buildRectForFloatRect(
+    const FloatRect& rect) {
+  return protocol::DOM::Rect::create()
+      .setX(rect.x())
+      .setY(rect.y())
+      .setWidth(rect.width())
+      .setHeight(rect.height())
+      .build();
+}
+
 }  // namespace
 
 class InspectorRevalidateDOMTask final
@@ -521,6 +533,77 @@ void InspectorDOMAgent::getDocument(
   *root = buildObjectForNode(m_document.get(), 2, m_documentNodeToIdMap.get());
 }
 
+void InspectorDOMAgent::getLayoutTreeNodes(
+    ErrorString* errorString,
+    std::unique_ptr<protocol::Array<protocol::DOM::LayoutTreeNode>>*
+        layoutTreeNodes) {
+  layoutTreeNodes->reset(new protocol::Array<protocol::DOM::LayoutTreeNode>);
+  visitLayoutTreeNodes(m_document.get(), *layoutTreeNodes->get());
+}
+
+void InspectorDOMAgent::visitLayoutTreeNodes(
+    Node* node,
+    protocol::Array<protocol::DOM::LayoutTreeNode>& layoutTreeNodes) {
+  for (; node; node = NodeTraversal::next(*node)) {
+    // Visit shadow dom nodes.
+    if (node->isElementNode()) {
+      const Element* element = toElement(node);
+      ElementShadow* elementShadow = element->shadow();
+      if (elementShadow) {
+        visitLayoutTreeNodes(&elementShadow->youngestShadowRoot(),
+                             layoutTreeNodes);
+      }
+    }
+
+    // Pierce iframe boundaries.
+    if (node->isFrameOwnerElement()) {
+      visitLayoutTreeNodes(
+          toHTMLFrameOwnerElement(node)->contentDocument()->documentElement(),
+          layoutTreeNodes);
+    }
+
+    LayoutObject* layoutObject = node->layoutObject();
+    if (!layoutObject)
+      continue;
+
+    int backendNodeId = DOMNodeIds::idForNode(node);
+    std::unique_ptr<protocol::DOM::LayoutTreeNode> layoutTreeNode =
+        protocol::DOM::LayoutTreeNode::create()
+            .setBackendNodeId(backendNodeId)
+            .setBoundingBox(buildRectForFloatRect(
+                node->isElementNode()
+                    ? FloatRect(toElement(node)->boundsInViewport())
+                    : layoutObject->absoluteBoundingBoxRect()))
+            .build();
+
+    if (layoutObject->isText()) {
+      LayoutText* layoutText = toLayoutText(layoutObject);
+      layoutTreeNode->setLayoutText(layoutText->text());
+      if (layoutText->hasTextBoxes()) {
+        std::unique_ptr<protocol::Array<protocol::DOM::InlineTextBox>>
+            inlineTextNodes(
+                new protocol::Array<protocol::DOM::InlineTextBox>());
+        for (const InlineTextBox* textBox = layoutText->firstTextBox(); textBox;
+             textBox = textBox->nextTextBox()) {
+          FloatRect localCoordsTextBoxRect(textBox->calculateBoundaries());
+          FloatRect absoluteCoordsTextBoxRect =
+              layoutObject->localToAbsoluteQuad(localCoordsTextBoxRect)
+                  .boundingBox();
+          inlineTextNodes->addItem(protocol::DOM::InlineTextBox::create()
+                                       .setStartCharacterIndex(textBox->start())
+                                       .setNumCharacters(textBox->len())
+                                       .setBoundingBox(buildRectForFloatRect(
+                                           absoluteCoordsTextBoxRect))
+                                       .build());
+        }
+        layoutTreeNode->setInlineTextNodes(std::move(inlineTextNodes));
+      }
+    }
+
+    layoutTreeNodes.addItem(std::move(layoutTreeNode));
+  }
+}
+
 void InspectorDOMAgent::pushChildNodesToFrontend(int nodeId, int depth) {
   Node* node = nodeForId(nodeId);
   if (!node || (!node->isElementNode() && !node->isDocumentNode() &&