Update DevTools Tracing.Start to accept trace config as a parameter

third_party/WebKit/Source/devtools/protocol.json

Index: third_party/WebKit/Source/devtools/protocol.json
diff --git a/third_party/WebKit/Source/devtools/protocol.json b/third_party/WebKit/Source/devtools/protocol.json
index 8ca06b8440503febf231b190c57ba0883171813b..add3cd1e79c5fe66a8cfe78ce74078a6309a9750 100644
--- a/third_party/WebKit/Source/devtools/protocol.json
+++ b/third_party/WebKit/Source/devtools/protocol.json
@@ -4824,16 +4824,56 @@
     },
     {
         "domain": "Tracing",
+        "types": [
+            {
+                "id": "RecordMode",
+                "type": "string",
+                "enum": ["recordUntilFull", "recordContinuously", "recordAsMuchAsPossible", "echoToConsole"],
+                "description": "The option that determines how the trace buffer stores data."

[petrcermak, 2016/03/14 18:05:09]

nit: I do NOT think the descriptions should start with "The". I think it should
just be "Option that ..."

[Zhen Wang, 2016/03/14 21:41:46]

Done.

+            },
+            {
+                "id": "MemoryDumpTrigger",
+                "type": "object",
+                "properties": [
+                    { "name": "mode", "type": "string", "optional": false, "description": "" },

[petrcermak, 2016/03/14 18:05:09]

Shouldn't we have an enum for this? How else will the user know what are valid
values???

Primiano: WDYT?

Also I think you should provide an actual description.

[Zhen Wang, 2016/03/14 21:41:46]

Updated this to an enum.

+                    { "name": "periodicIntervalMs", "type": "integer", "optional": false, "description": "" }

[petrcermak, 2016/03/14 18:05:09]

I think you should provide an actual description.

[Zhen Wang, 2016/03/14 21:41:45]

How about the new one?

+                ],
+                "description": "The configurations that trigger memory dump."

[petrcermak, 2016/03/14 18:05:09]

ditto drop "The"

[Zhen Wang, 2016/03/14 21:41:46]

Done.

+            },
+            {
+                "id": "MemoryDumpConfig",
+                "type": "object",
+                "properties": [
+                    { "name": "triggers", "type": "array", "items": { "$ref": "MemoryDumpTrigger" }, "optional": false, "description": "The configurations that trigger memory dump." }
+                ],
+                "description": "The configuration for memory dump. Used only when \"memory-infra\" category is enabled."

[petrcermak, 2016/03/14 18:05:09]

ditto drop "The"

[Zhen Wang, 2016/03/14 21:41:45]

Done.

+            },
+            {
+                "id": "TraceConfig",
+                "type": "object",
+                "properties": [
+                    { "name": "recordMode", "$ref": "RecordMode", "optional": true, "description": "Controls how the trace buffer stores data." },
+                    { "name": "enableSampling", "type": "boolean", "optional": true, "description": "Turns on JavaScript stack sampling." },
+                    { "name": "enableSystrace", "type": "boolean", "optional": true, "description": "Turns on system tracing." },
+                    { "name": "enableArgumentFilter", "type": "boolean", "optional": true, "description": "Turns on argument filter." },
+                    { "name": "includedCategories", "type": "array", "items": { "type": "string" }, "optional": true, "description": "The category filters that are included." },

[petrcermak, 2016/03/14 18:05:09]

ditto drop "The"

[Zhen Wang, 2016/03/14 21:41:45]

Done.

+                    { "name": "excludedCategories", "type": "array", "items": { "type": "string" }, "optional": true, "description": "The category filters that are excluded." },

[petrcermak, 2016/03/14 18:05:09]

ditto drop "The"

[Zhen Wang, 2016/03/14 21:41:46]

Done.

+                    { "name": "syntheticDelays", "type": "array", "items": { "type": "string" }, "optional": true, "description": "The configuration to synthesize the delays in tracing." },

[petrcermak, 2016/03/14 18:05:09]

Shouldn't this be an enum??

[petrcermak, 2016/03/14 18:05:09]

ditto drop "The"

[Zhen Wang, 2016/03/14 21:41:45]

No. I think this is different. Synthetic delays are specified as list of
strings, like categories. And the string contains event name, which can be
arbitrary.
https://code.google.com/p/chromium/codesearch#chromium/src/base/trace_event/t...

+                    { "name": "memoryDumpConfig", "$ref": "MemoryDumpConfig", "optional": true, "description": "The configuration for memory dump. Used only when \"memory-infra\" category is enabled." }

[petrcermak, 2016/03/14 18:05:09]

ditto drop "The"

[Zhen Wang, 2016/03/14 21:41:46]

Done.

+                ]
+            }
+        ],
         "commands": [
             {
                 "name": "start",
                 "async": true,
                 "description": "Start trace events collection.",
                 "parameters": [
-                    { "name": "categories", "type": "string", "optional": true, "description": "Category/tag filter" },
-                    { "name": "options", "type": "string", "optional": true, "description": "Tracing options" },
+                    { "name": "categories", "type": "string", "optional": true, "deprecated": true, "description": "Category/tag filter" },
+                    { "name": "options", "type": "string", "optional": true, "deprecated": true, "description": "Tracing options" },
                     { "name": "bufferUsageReportingInterval", "type": "number", "optional": true, "description": "If set, the agent will issue bufferUsage events at this interval, specified in milliseconds" },
-                    { "name": "transferMode", "type": "string", "enum": ["ReportEvents", "ReturnAsStream"], "optional": true, "description": "Whether to report trace events as series of dataCollected events or to save trace to a stream (defaults to <code>ReportEvents</code>)." }
+                    { "name": "transferMode", "type": "string", "enum": ["ReportEvents", "ReturnAsStream"], "optional": true, "description": "Whether to report trace events as series of dataCollected events or to save trace to a stream (defaults to <code>ReportEvents</code>)." },
+                    { "name": "traceConfig", "$ref": "TraceConfig", "optional": true, "description": "" }
                 ],
                 "handlers": ["browser", "renderer"]
             },