Adds DevTools commands for forced viewport override.

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

 {
     "version": { "major": "1", "minor": "1" },
     "domains": [{
         "domain": "Inspector",
         "hidden": true,
         "types": [],
         "commands": [
             {
                 "name": "enable",
                 "description": "Enables inspector domain notifications.",
@@ skipping 729 matching lines @@
                     { "name": "screenOrientation", "$ref": "ScreenOrientation", "optional": true, "description": "Screen orientation override." }
                 ],
                 "handlers": ["browser"]
             },
             {
                 "name": "clearDeviceMetricsOverride",
                 "description": "Clears the overriden device metrics.",
                 "handlers": ["browser"]
             },
             {
+                "name": "setCompositedAreaOverride",

[Sami, 2016/08/11 10:09:07]

Alternative name idea: setVisibleAreaOverride

Not sure which I like better so we could keep this one :)

[Eric Seckler, 2016/08/11 11:34:45]

Renamed to VisualTransformOverride, Thanks!

+                "description": "Overrides the visible area of the page in the frame. In effect, moves the specified area of the page into the top-left corner of the frame.",
+                "parameters": [
+                    { "name": "x", "type": "number", "description": "X coordinate of top-left corner of the area (CSS pixels)." },
+                    { "name": "y", "type": "number", "description": "Y coordinate of top-left corner of the area (CSS pixels)." },
+                    { "name": "width", "type": "number", "description": "Width of the area (CSS pixels)." },
+                    { "name": "height", "type": "number", "description": "Height of the area (CSS pixels)." },
+                    { "name": "scale", "type": "number", "optional": true, "description": "Scale to apply to the selected area (default 1.0)." }
+                ]
+            },
+            {
+                "name": "clearCompositedAreaOverride",
+                "description": "Clears any active composited area override."
+            },
+            {
                 "name": "resetPageScaleFactor",
                 "description": "Requests that page scale factor is reset to initial values."
             },
             {
                 "name": "setPageScaleFactor",
                 "description": "Sets a specified page scale factor.",
                 "parameters": [
                     { "name": "pageScaleFactor", "type": "number", "description": "Page scale factor." }
                 ]
             },
@@ skipping 3697 matching lines @@
                 "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"]
             }
         ]
     }]
 }