Implement window management devtools commands for headless.

headless/public/headless_browser.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef HEADLESS_PUBLIC_HEADLESS_BROWSER_H_
 #define HEADLESS_PUBLIC_HEADLESS_BROWSER_H_
 
 #include <memory>
 #include <string>
 #include <unordered_map>
@@ skipping 146 matching lines @@
   std::string user_agent;
 
   // Address of the HTTP/HTTPS proxy server to use. The system proxy settings
   // are used by default.
   net::HostPortPair proxy_server;
 
   // Comma-separated list of rules that control how hostnames are mapped. See
   // chrome::switches::kHostRules for a description for the format.
   std::string host_resolver_rules;
 
-  // Default window size. This is also used to create the window tree host and
-  // as initial screen size. Defaults to 800x600.
+  // Default window size. This is also used to create the window tree host.
+  // Defaults to 800x600.
   gfx::Size window_size;
 
+  // Screen size. This is used to initialize screen size for web_contents and
+  // support window management devtools commands. Defaults to 1,920x1,080.

[Sami, 2017/05/22 16:30:57]

This isn't reflected to JavaScript (i.e., screen.width/height) as far as I can
tell. Maybe add a TODO for that?

+  gfx::Size screen_size;
+
   // Path to user data directory, where browser will look for its state.
   // If empty, default directory (where the binary is located) will be used.
   base::FilePath user_data_dir;
 
   // Run a browser context in an incognito mode. Enabled by default.
   bool incognito_mode;
 
   // Set a callback that is invoked to override WebPreferences for RenderViews
   // created within the HeadlessBrowser. Called whenever the WebPreferences of a
   // RenderView change. Executed on the browser main thread.
@@ skipping 97 matching lines @@
 // the main loop, it will only return after HeadlessBrowser::Shutdown() is
 // called, returning the exit code for the process. It is not possible to
 // initialize the browser again after it has been torn down.
 HEADLESS_EXPORT int HeadlessBrowserMain(
     HeadlessBrowser::Options options,
     const base::Callback<void(HeadlessBrowser*)>& on_browser_start_callback);
 
 }  // namespace headless
 
 #endif  // HEADLESS_PUBLIC_HEADLESS_BROWSER_H_