Implement window management devtools commands for headless.

headless/lib/browser/headless_browser_impl_aura.cc

Index: headless/lib/browser/headless_browser_impl_aura.cc
diff --git a/headless/lib/browser/headless_browser_impl_aura.cc b/headless/lib/browser/headless_browser_impl_aura.cc
index 57a0f77c7918b6bcfd7df9277934a221dc564897..f4494d75a1d0dc62e5293e1465fbe8cca3096a08 100644
--- a/headless/lib/browser/headless_browser_impl_aura.cc
+++ b/headless/lib/browser/headless_browser_impl_aura.cc
@@ -18,7 +18,7 @@
 namespace headless {
 
 void HeadlessBrowserImpl::PlatformInitialize() {
-  HeadlessScreen* screen = HeadlessScreen::Create(options()->window_size);
+  HeadlessScreen* screen = HeadlessScreen::Create(options()->screen_size);
   display::Screen::SetScreenInstance(screen);
 
   // TODO(eseckler): We shouldn't share clipboard contents across WebContents
@@ -33,9 +33,10 @@ 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) {
-  gfx::Rect initial_rect(initial_size);
+  gfx::Rect initial_rect(initial_window_size);
 
   auto window_tree_host =
       base::MakeUnique<HeadlessWindowTreeHost>(initial_rect);
@@ -54,7 +55,7 @@ void HeadlessBrowserImpl::PlatformInitializeWebContents(
   content::RenderWidgetHostView* host_view =
       web_contents->web_contents()->GetRenderWidgetHostView();
   if (host_view)
-    host_view->SetSize(initial_size);
+    host_view->SetSize(screen_size);

[Eric Seckler, 2017/05/22 19:13:40]

Hm, I don't quite understand screen_size. - Why does the RWHV get the screen
size?

I believe the RWHV should have the same size as the WebContents.

 }
 
 }  // namespace headless