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

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 a88f4d115fdb2a70fdaf014da78fa7c45c2d4951..e9088ab9a4ffaeddff8801c6ba58988624b67683 100644
--- a/third_party/WebKit/Source/core/inspector/browser_protocol.json
+++ b/third_party/WebKit/Source/core/inspector/browser_protocol.json
@@ -2999,11 +2999,11 @@
                 "id": "LayoutTreeNode",
                 "type": "object",
                 "properties": [
-                    { "name": "nodeId", "$ref": "DOM.NodeId", "description": "The id of the related DOM node matching one from DOM.GetDocument." },
+                    { "name": "nodeId", "$ref": "DOM.NodeId", "description": "The id of the related DOM node in the domNodes array returned by getDocumentSnapshot." },

[pfeldman, 2017/05/31 17:56:37]

It can't be of type NodeId - NodeId is a node handle type which it no longer is.
It is now the "index" in the domNodes array.

                     { "name": "boundingBox", "$ref": "DOM.Rect", "description": "The absolute position bounding box." },
                     { "name": "layoutText", "type": "string", "optional": true, "description": "Contents of the LayoutText if any" },
                     { "name": "inlineTextNodes", "type": "array", "optional": true, "items": { "$ref": "InlineTextBox" }, "description": "The post layout inline text nodes, if any." },
-                    { "name": "styleIndex", "type": "integer", "optional": true, "description": "Index into the computedStyles array returned by getLayoutTreeAndStyles." }
+                    { "name": "styleIndex", "type": "integer", "optional": true, "description": "Index into the computedStyles array returned by getDocumentSnapshot." }
                 ],
                 "description": "Details of an element in the DOM tree with a LayoutObject.",
                 "experimental": true
@@ -3211,15 +3211,18 @@
                 "experimental": true
             },
             {
-                "name": "getLayoutTreeAndStyles",
+                "name": "getDocumentSnapshot",
                 "parameters": [
-                    { "name": "computedStyleWhitelist", "type": "array", "items": { "type": "string" }, "description": "Whitelist of computed styles to return." }
+                    { "name": "computedStyleWhitelist", "type": "array", "items": { "type": "string" }, "description": "Whitelist of computed styles to return." },
+                    { "name": "domDepth", "type": "integer", "optional": true, "description": "The maximum depth at which children should be retrieved, defaults to 1. Use -1 for the entire subtree or provide an integer larger than 0." },

[pfeldman, 2017/05/31 17:56:37]

it is called depth everywhere else.

+                    { "name": "pierce", "type": "boolean", "optional": true, "description": "Whether or not iframes and shadow roots should be traversed when returning the subtree (default is false)." }
                 ],
                 "returns": [
-                    { "name": "layoutTreeNodes", "type": "array", "items": { "$ref": "LayoutTreeNode" } },
-                    { "name": "computedStyles", "type": "array", "items": { "$ref": "ComputedStyle" } }
+                    { "name": "domNodes", "type": "array", "items": { "$ref": "DOM.Node" }, "description": "The nodes in the DOM tree. These nodes will also be considered as known to the DOM domain client in the future." },

[pfeldman, 2017/05/31 17:56:37]

I don't think it makes much sense - we should not combine the "inspection" and
"scripting/automation" semantics here. It is unlikely that the snapshot client
wants to receive all the node-related notifications post the snapshot retrieval
and you are forcing this.

+                    { "name": "layoutTreeNodes", "type": "array", "items": { "$ref": "LayoutTreeNode" }, "description": "The nodes in the layout tree." },
+                    { "name": "computedStyles", "type": "array", "items": { "$ref": "ComputedStyle" }, "description": "Whitelisted ComputedStyle properties for each node in the layout tree." }
                 ],
-                "description": "For the main document and any content documents, return the LayoutTreeNodes and a whitelisted subset of the computed style. It only returns pushed nodes, on way to pull all nodes is to call DOM.getDocument with a depth of -1.",
+                "description": "Returns a document snapshot, including the DOM tree of the root node up to the given depth in a flattened array, as well as layout and white-listed computed style information for the nodes. Requires that the DOM domain is enabled.",
                 "experimental": true
             },
             {