[DevTools] Support multiple sessions in Target domain

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

 {
     "version": { "major": "1", "minor": "2" },
     "domains": [{
         "domain": "Inspector",
         "experimental": true,
         "types": [],
         "commands": [
             {
                 "name": "enable",
                 "description": "Enables inspector domain notifications."
@@ skipping 3534 matching lines @@
     {
         "domain": "Target",
         "description": "Supports additional targets discovery and allows to attach to them.",
         "experimental": true,
         "types": [
             {
                 "id": "TargetID",
                 "type": "string"
             },
             {
+                "id": "SessionID",
+                "type": "string"
+            },
+            {
                 "id": "BrowserContextID",
                 "type": "string"
             },
             {
                 "id": "TargetInfo",
                 "type": "object",
                 "properties": [
                     { "name": "targetId", "$ref": "TargetID" },
                     { "name": "type", "type": "string" },
                     { "name": "title", "type": "string" },
@@ skipping 33 matching lines @@
             },
             {
                 "name": "setRemoteLocations",
                 "description": "Enables target discovery for the specified locations, when <code>setDiscoverTargets</code> was set to <code>true</code>.",
                 "parameters": [
                     { "name": "locations", "type": "array", "items": { "$ref": "RemoteLocation" }, "description": "List of remote locations." }
                 ]
             },
             {
                 "name": "sendMessageToTarget",
-                "description": "Sends protocol message to the target with given id.",
+                "description": "Sends protocol message to the session with given id.",
                 "parameters": [
-                    { "name": "targetId", "$ref": "TargetID" },
+                    { "name": "sessionId", "$ref": "SessionID" },
                     { "name": "message", "type": "string" }
                 ]
             },
             {
                 "name": "getTargetInfo",
                 "description": "Returns information about a target.",
                 "parameters": [
                     { "name": "targetId", "$ref": "TargetID" }
                 ],
                 "returns": [
@@ skipping 17 matching lines @@
                     { "name": "success", "type": "boolean" }
                 ]
             },
             {
                 "name": "attachToTarget",
                 "description": "Attaches to the target with given id.",
                 "parameters": [
                     { "name": "targetId", "$ref": "TargetID" }
                 ],
                 "returns": [
-                    { "name": "success", "type": "boolean", "description": "Whether attach succeeded." }
+                    { "name": "sessionId", "$ref": "SessionID", "optional": true, "description": "Id assigned to the session, only present if attached successfully." }
                 ]
             },
             {
                 "name": "detachFromTarget",
-                "description": "Detaches from the target with given id.",
+                "description": "Detaches from the session with given id.",
                 "parameters": [
-                    { "name": "targetId", "$ref": "TargetID" }
+                    { "name": "sessionId", "$ref": "TargetID" }

[caseq, 2017/06/27 18:29:30]

s/TargetID/SessionID/

                 ]
             },
             {
                 "name": "createBrowserContext",
                 "description": "Creates a new empty BrowserContext. Similar to an incognito profile but you can have more than one.",
                 "returns": [
                     { "name": "browserContextId", "$ref": "BrowserContextID", "description": "The id of the context created." }
                 ]
             },
             {
@@ skipping 39 matching lines @@
                 "name": "targetDestroyed",
                 "description": "Issued when a target is destroyed.",
                 "parameters": [
                     { "name": "targetId", "$ref": "TargetID" }
                 ]
             },
             {
                 "name": "attachedToTarget",
                 "description": "Issued when attached to target because of auto-attach or <code>attachToTarget</code> command.",
                 "parameters": [
+                    { "name": "sessionId", "$ref": "SessionID", "description": "Id assigned to the session for future communication." },
                     { "name": "targetInfo", "$ref": "TargetInfo" },
                     { "name": "waitingForDebugger", "type": "boolean" }
                 ]
             },
             {
                 "name": "detachedFromTarget",
-                "description": "Issued when detached from target for any reason (including <code>detachFromTarget</code> command).",
+                "description": "Issued when detached from session for any reason (including <code>detachFromTarget</code> command).",
                 "parameters": [
-                    { "name": "targetId", "$ref": "TargetID" }
+                    { "name": "sessionId", "$ref": "SessionID" }
                 ]
             },
             {
                 "name": "receivedMessageFromTarget",
-                "description": "Notifies about new protocol message from attached target.",
+                "description": "Notifies about a new protocol message from the session (as reported in <code>attachedToTarget</code> event).",
                 "parameters": [
-                    { "name": "targetId", "$ref": "TargetID" },
+                    { "name": "sessionId", "$ref": "SessionID" },
                     { "name": "message", "type": "string" }
                 ]
             }
         ]
     },
     {
         "domain": "ServiceWorker",
         "experimental": true,
         "types": [
             {
@@ skipping 1086 matching lines @@
                 "parameters": [
                     { "name": "windowId", "$ref": "WindowID", "description": "Browser window id." }
                 ],
                 "returns": [
                     { "name": "bounds", "$ref": "Bounds", "description": "Bounds information of the window. When window state is 'minimized', the restored window position and size are returned." }
                 ]
             }
         ]
     }]
 }