Add a DOM.getLayoutTreeNodes devtools command

third_party/WebKit/Source/core/inspector/browser_protocol.json

Index: third_party/WebKit/Source/core/inspector/browser_protocol.json
diff --git a/third_party/WebKit/Source/core/inspector/browser_protocol.json b/third_party/WebKit/Source/core/inspector/browser_protocol.json
index 20068fb27b640018359b555452b6b0ed3f83f7bb..63bfe0b2069bfe2c8ce4a195719ae2d5166f3a8b 100644
--- a/third_party/WebKit/Source/core/inspector/browser_protocol.json
+++ b/third_party/WebKit/Source/core/inspector/browser_protocol.json
@@ -2045,6 +2045,28 @@
                 "description": "DOM interaction is implemented in terms of mirror objects that represent the actual DOM nodes. DOMNode is a base node mirror type."
             },
             {
+                "id": "InlineTextBox",
+                "type": "object",
+                "properties": [
+                    { "name": "boundingBox", "$ref": "Rect", "description": "The absolute position bounding box." },
+                    { "name": "text", "type": "string", "description": "Post layout inline text snippet." }
+                ],
+                "description": "Details of post layout rendered text positions.",
+                "experimental": true
+            },
+            {
+                "id": "RenderTreeNode",
+                "type": "object",
+                "properties": [
+                    { "name": "backendNodeId", "$ref": "BackendNodeId", "description": "The BackendNodeId of the related DOM node." },
+                    { "name": "boundingBox", "$ref": "Rect", "description": "The absolute position bounding box." },
+                    { "name": "layoutText", "type": "string", "optional": true, "description": "Contents of the LayoutText if any" },
+                    { "name": "inlineTextNodes", "type": "array", "optional": true, "items": { "$ref": "InlineTextBox" }, "description": "The post layout inline text nodes, if any." }
+                ],
+                "description": "Details of an element in the DOM tree with a LayoutObject.",
+                "experimental": true
+            },
+            {
                 "id": "RGBA",
                 "type": "object",
                 "properties": [
@@ -2150,6 +2172,14 @@
                 "description": "Returns the root DOM node to the caller."
             },
             {
+                "name": "getRenderTreeNodes",

[Sami, 2016/09/16 12:31:59]

Should we call this getLayoutTreeNodes instead to avoid the confusion Pavel
mentioned? We could think about getting the render (paint) tree later but it
doesn't seem necessary now.

[alex clarke (OOO till 29th), 2016/09/20 10:58:59]

Done

+                "returns": [
+                    { "name": "renderTreeNodes", "type": "array", "items": { "$ref": "RenderTreeNode" } }
+                ],
+                "description": "Returns the RenderTree to the caller.",
+                "experimental": true
+            },
+            {
                 "name": "collectClassNamesFromSubtree",
                 "parameters": [
                     { "name": "nodeId", "$ref": "NodeId", "description": "Id of the node to collect class names." }