[DevTools] Implement screen orientation override.

Source/devtools/protocol.json

 {
     "version": { "major": "1", "minor": "1" },
     "domains": [{
         "domain": "Inspector",
         "hidden": true,
         "types": [],
         "commands": [
             {
                 "name": "enable",
                 "description": "Enables inspector domain notifications.",
@@ skipping 4631 matching lines @@
                     { "name": "gamma", "type": "number", "description": "Mock gamma"}
                 ]
             },
             {
                 "name": "clearDeviceOrientationOverride",
                 "description": "Clears the overridden Device Orientation."
             }
         ]
     },
     {
+        "domain": "ScreenOrientation",
+        "hidden": true,
+        "types": [
+            {
+                "id": "OrientationType",
+                "type": "string",
+                "enum": ["portraitPrimary", "portraitSecondary", "landscapePrimary", "landscapeSecondary"],
+                "description": "Orientation type"
+            }
+        ],
+        "commands": [
+            {
+                "name": "setScreenOrientationOverride",
+                "description": "Overrides the Screen Orientation.",
+                "parameters": [
+                    { "name": "angle", "type": "integer", "description": "Orientation angle" },
+                    { "name": "type", "$ref": "OrientationType", "description": "Orientation type" }
+                ]
+            },
+            {
+                "name": "clearScreenOrientationOverride",
+                "description": "Clears the overridden Screen Orientation."
+            }
+        ]
+    },
+    {
         "domain": "Tracing",
         "commands": [
             {
                 "name": "start",
                 "async": true,
                 "description": "Start trace events collection.",
                 "parameters": [
                     { "name": "categories", "type": "string", "optional": true, "description": "Category/tag filter" },
                     { "name": "options", "type": "string", "optional": true, "description": "Tracing options" },
                     { "name": "bufferUsageReportingInterval", "type": "number", "optional": true, "description": "If set, the agent will issue bufferUsage events at this interval, specified in milliseconds" }
@@ skipping 386 matching lines @@
                 "description": "The security state of the page changed.",
                 "parameters": [
                     { "name": "securityState", "$ref": "SecurityState", "description": "Security state." },
                     { "name": "explanations", "type": "array", "items": { "$ref": "SecurityStateExplanation" }, "description": "List of explanations for the security state. If the overall security state is `insecure` or `warning`, at least one corresponding explanation should be included.", "optional": true }
                 ],
                 "handlers": ["browser"]
             }
         ]
     }]
 }