Adds enableVirtualTime and setVirtualTimePolicy To Emulation domain.

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 92da94fe533f82d51308b740d9fe1a991129fdd4..84d0759b10942a0d8b1f66e7fb09b71a3e6dbe2c 100644
--- a/third_party/WebKit/Source/core/inspector/browser_protocol.json
+++ b/third_party/WebKit/Source/core/inspector/browser_protocol.json
@@ -670,6 +670,16 @@
                     { "name": "type",  "type": "string", "enum": ["portraitPrimary", "portraitSecondary", "landscapePrimary", "landscapeSecondary"], "description": "Orientation type." },
                     { "name": "angle",  "type": "integer", "description": "Orientation angle." }
                 ]
+            },
+            {
+                "id": "VirtualTimePolicy",
+                "type": "string",
+                "enum": [
+                    "advance",
+                    "pause",
+                    "pauseIfNetworkFetchesPending"
+                ],
+                "description": "For a description of the virtual time policies see: https://docs.google.com/document/d/1y9KDT_ZEzT7pBeY6uzVt1dgKlwc1OB_vY4NZO1zBQmo"

[dgozman, 2016/07/05 15:30:35]

We prefer to not include links here, since it's published for end-users. Can we
copy descriptions from the last table in the document?

[alex clarke (OOO till 29th), 2016/07/05 16:51:23]

Done.

             }
         ],
         "commands": [
@@ -761,6 +771,19 @@
                     { "name": "result", "type": "boolean", "description": "True if emulation is supported." }
                 ],
                 "handlers": ["browser"]
+            },
+            {
+                "name": "enableVirtualTime",

[dgozman, 2016/07/05 15:30:35]

Why can't we disable it?

[alex clarke (OOO till 29th), 2016/07/05 16:51:23]

We could but I'm not sure it's a good idea to allow it.  The reason being the
virtual time base could get far ahead of real time and if we disable virtual
time that would leave any timers posted "stranded in the future".

+                "description": "Turns on virtual time for all frames, replacing real-time with a synthetic time source.",
+                "hidden": true
+            },
+            {
+                "name": "setVirtualTimePolicy",

[dgozman, 2016/07/05 15:30:35]

Should we add "disabled" to the list of policies and have just a single method?
Client will have to enable and immediately set the policy anyway. Let's make any
policy automatically enable virtual time?

[alex clarke (OOO till 29th), 2016/07/05 16:51:23]

See above.


to the list of policies and have just a single method?
Sure we can reduce this to a single method.

+                "description": "Sets the current virtual time policy for all frames.",
+                "parameters": [
+                    { "name": "policy", "$ref": "VirtualTimePolicy" }
+                ],
+                "hidden": true
             }
         ]
     },