Implement window management devtools commands for headless.

headless/lib/browser/headless_browser_impl_mac.mm

Index: headless/lib/browser/headless_browser_impl_mac.mm
diff --git a/headless/lib/browser/headless_browser_impl_mac.mm b/headless/lib/browser/headless_browser_impl_mac.mm
index f5f5f7e83e749fa40498a41c2f9efe5254e9261f..d335fc89ea90b3cfe3b43a51e9bc4ee2ee0714eb 100644
--- a/headless/lib/browser/headless_browser_impl_mac.mm
+++ b/headless/lib/browser/headless_browser_impl_mac.mm
@@ -14,12 +14,14 @@ void HeadlessBrowserImpl::PlatformInitialize() {}
 void HeadlessBrowserImpl::PlatformCreateWindow() {}
 
 void HeadlessBrowserImpl::PlatformInitializeWebContents(
-    const gfx::Size& initial_size,
+    const gfx::Size& initial_window_size,
+    const gfx::Size& screen_size,
     HeadlessWebContentsImpl* web_contents) {
   NSView* web_view = web_contents->web_contents()->GetNativeView();
   [web_view setAutoresizingMask:(NSViewWidthSizable | NSViewHeightSizable)];
 
-  NSRect frame = NSMakeRect(0, 0, initial_size.width(), initial_size.height());
+  NSRect frame = NSMakeRect(0, 0, initial_window_size.width(),
+                            initial_window_size.height());
   [web_view setFrame:frame];
   return;
 }