[headless] Use individual aura::WindowTreeHosts per WebContents.

headless/lib/browser/headless_browser_impl_aura.cc

 // Copyright 2017 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.
 
 #include "headless/lib/browser/headless_browser_impl.h"
 
 #include "content/public/browser/render_widget_host_view.h"
 #include "content/public/browser/web_contents.h"
 #include "headless/lib/browser/headless_clipboard.h"
-#include "headless/lib/browser/headless_focus_client.h"
 #include "headless/lib/browser/headless_screen.h"
-#include "ui/aura/client/focus_client.h"
 #include "ui/aura/env.h"
 #include "ui/aura/window.h"
 #include "ui/base/clipboard/clipboard.h"
 #include "ui/display/screen.h"
 #include "ui/events/devices/device_data_manager.h"
 #include "ui/gfx/geometry/size.h"
 
 namespace headless {
 
 void HeadlessBrowserImpl::PlatformInitialize() {
   HeadlessScreen* screen = HeadlessScreen::Create(options()->window_size);
   display::Screen::SetScreenInstance(screen);
 
+  // TODO(eseckler): We shouldn't share clipboard contents across WebContents
+  // (or at least BrowserContexts).

[Sami, 2017/03/31 17:53:51]

N.B. this might be tricky to pull off -- after all even incognito and regular
windows share a clipboard.

   ui::Clipboard::SetClipboardForCurrentThread(
       base::MakeUnique<HeadlessClipboard>());
 }
 
 void HeadlessBrowserImpl::PlatformCreateWindow() {
   DCHECK(aura::Env::GetInstance());
   ui::DeviceDataManager::CreateInstance();
-
-  window_tree_host_.reset(
-      new HeadlessWindowTreeHost(gfx::Rect(options()->window_size)));
-  window_tree_host_->InitHost();
-  window_tree_host_->window()->Show();
-  window_tree_host_->SetParentWindow(window_tree_host_->window());
-
-  focus_client_.reset(new HeadlessFocusClient());
-  aura::client::SetFocusClient(window_tree_host_->window(),
-                               focus_client_.get());
 }
 
 void HeadlessBrowserImpl::PlatformInitializeWebContents(
     const gfx::Size& initial_size,
-    content::WebContents* web_contents) {
-  gfx::NativeView contents = web_contents->GetNativeView();
-  gfx::NativeWindow parent_window = window_tree_host_->window();
+    HeadlessWebContentsImpl* web_contents) {
+  gfx::Rect initial_rect(initial_size);
+
+  auto window_tree_host =
+      base::MakeUnique<HeadlessWindowTreeHost>(initial_rect);
+  window_tree_host->InitHost();
+  gfx::NativeWindow parent_window = window_tree_host->window();
+  parent_window->Show();
+  window_tree_host->SetParentWindow(parent_window);
+  web_contents->set_window_tree_host(std::move(window_tree_host));
+
+  gfx::NativeView contents = web_contents->web_contents()->GetNativeView();
   DCHECK(!parent_window->Contains(contents));
   parent_window->AddChild(contents);
   contents->Show();
-  contents->SetBounds(gfx::Rect(initial_size));
+  contents->SetBounds(initial_rect);
 
   content::RenderWidgetHostView* host_view =
-      web_contents->GetRenderWidgetHostView();
+      web_contents->web_contents()->GetRenderWidgetHostView();
   if (host_view)
     host_view->SetSize(initial_size);
 }
 
 }  // namespace headless