Resize DevTools target frames.

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..b15d5f505b32246e1c4f22bd7ca9a7bfe6cf071d 100644
--- a/third_party/WebKit/Source/core/inspector/browser_protocol.json
+++ b/third_party/WebKit/Source/core/inspector/browser_protocol.json
@@ -758,6 +758,24 @@
                 ]
             },
             {
+                "name": "getFrameSize",

[pfeldman, 2016/08/11 14:34:17]

Do you expect getFrameSize to be used in automation? I was thinking that since
we automate the page, we create it with given size and set size, we should be
aware of it. So I would drop it.

[Eric Seckler, 2016/08/11 14:45:50]

It would allow us to take partial screenshots without prior knowledge of the
current frame size. I think it'd be primarily useful in non-headless
environments, but also in cases where the page can change the browser window
size via window.resizeTo().

I'm thinking of its use in this way:
- Get current frame size.
- Put device metrics override in place with obtained frame size (so that
setFrameSize doesn't affect page layout).
- Set frame size, which resizes the RWHV to screenshot size.
- Take screenshot.

But since it's not necessary for the common use cases in headless, I'm happy to
remove it if you think it's not useful.

+                "description": "Returns the size of the target's (non-overridden) frame.",
+                "returns": [
+                    { "name": "width", "type": "integer", "description": "Frame width (DIP)." },
+                    { "name": "height", "type": "integer", "description": "Frame height (DIP)." }
+                ],
+                "handlers": ["browser"]
+            },
+            {
+                "name": "setFrameSize",
+                "description": "Resize the target's frame. Note that this does not affect the frame's container (e.g. browser window).",
+                "parameters": [
+                    { "name": "width", "type": "integer", "description": "Frame width (DIP)." },
+                    { "name": "height", "type": "integer", "description": "Frame height (DIP)." }
+                ],
+                "handlers": ["browser"]
+            },
+            {
                 "name": "setScriptExecutionDisabled",
                 "description": "Switches script execution in the page.",
                 "parameters": [
@@ -4319,8 +4337,8 @@
                 "description": "Creates a new page.",
                 "parameters": [
                     { "name": "url", "type": "string", "description": "The initial URL the page will be navigated to." },
-                    { "name": "width", "type": "integer", "description": "Window width (headless chrome only).", "optional": true },
-                    { "name": "height", "type": "integer", "description": "Window height (headless chrome only).", "optional": true },
+                    { "name": "width", "type": "integer", "description": "Frame width (DIP).", "optional": true },
+                    { "name": "height", "type": "integer", "description": "Frame height (DIP).", "optional": true },
                     { "name": "browserContextId", "$ref": "BrowserContextID", "description": "The browser context to create the page in (headless chrome only).", "optional": true }
                 ],
                 "returns": [