Adds DevTools commands for forced viewport override.

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 d4421424d10881a3da18992ade69f5798072a1be..349f208182d3fdced5feedad478228b69965e18e 100644
--- a/third_party/WebKit/Source/core/inspector/browser_protocol.json
+++ b/third_party/WebKit/Source/core/inspector/browser_protocol.json
@@ -747,6 +747,21 @@
                 "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."
             },