DevTools: provide an option to return traces as streams

content/browser/devtools/browser_protocol.json

 {
     "version": { "major": "1", "minor": "0" },
     "domains": [{
         "domain": "SystemInfo",
         "description": "The SystemInfo domain defines methods and events for querying low-level system information.",
         "hidden": true,
         "types": [
             {
                 "id": "GPUDevice",
                 "type": "object",
@@ skipping 59 matching lines @@
             {
                 "name": "accepted",
                 "description": "Informs that port was successfully bound and got a specified connection id.",
                 "parameters": [
                     {"name": "port", "type": "integer", "description": "Port number that was successfully bound." },
                     {"name": "connectionId", "type": "string", "description": "Connection id to be used." }
                 ],
                 "handlers": ["browser"]
             }
         ]
+    },
+    {
+        "domain": "IO",

[dgozman, 2015/08/24 20:45:44]

This domain does conceptually belong to renderer protocol, but this way it's
easy (until the repo merge). Add a TODO to move it after merge?

+        "description": "Input/Output operations for streams produced by DevTools.",
+        "hidden": true,
+        "commands": [
+            {
+                "name": "read",
+                "description": "Read a chunk of a stream",
+                "async": true,
+                "parameters": [
+                    { "name": "id", "type": "string", "description": "Identifier of a stream to read." },

[pfeldman, 2015/08/24 18:17:55]

Lets introduce a handle type.

+                    { "name": "offset", "type": "integer", "optional": true, "description": "Seek to specified offset before reading (if not specificed, proceed with offset following the last read)." },
+                    { "name": "size", "type": "integer", "optional": true,  "description": "Maximum number of bytes to read (left upon the agent discretion if not specified)." }
+                ],
+                "returns": [
+                    { "name": "data", "type": "string", "description": "Data that were read." },
+                    { "name": "eof", "type": "boolean", "description": "Set if the end-of-file condition occured while reading." }
+                ],
+                "handlers": ["browser"]
+            },
+            {
+                "name": "close",
+                "description": "Closes a stream, discard any temporary backing storage.",
+                "parameters": [
+                    { "name": "id", "type": "string", "description": "Identifier of a stream to close." }
+                ],
+                "handlers": ["browser"]
+            }
+        ]
     }]
 }