Add support for a virtual display on ChromeOS

content/browser/media/capture/virtual_display_capturer.cc

Index: content/browser/media/capture/virtual_display_capturer.cc
diff --git a/content/browser/media/capture/virtual_display_capturer.cc b/content/browser/media/capture/virtual_display_capturer.cc
new file mode 100644
index 0000000000000000000000000000000000000000..f9410814807c52ddabac037da0add343177ba407
--- /dev/null
+++ b/content/browser/media/capture/virtual_display_capturer.cc
@@ -0,0 +1,89 @@
+// 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.
+
+#include "content/browser/media/capture/virtual_display_capturer.h"
+
+#include "base/logging.h"
+#include "base/sys_info.h"
+#include "base/timer/timer.h"
+#include "content/browser/media/capture/aura_window_capture_machine.h"
+#include "content/browser/media/capture/content_video_capture_device_core.h"
+#include "content/public/browser/browser_thread.h"
+#include "ui/aura/window.h"
+#include "ui/display/chromeos/display_configurator.h"
+#include "ui/gfx/screen.h"
+
+namespace content {
+
+namespace {
+
+void EnableVirtualDisplay(const gfx::Size& size) {
+  ui::DisplayConfigurator::GetInstance()->EnableVirtualDisplay(size);
+}
+
+void DisableVirtualDisplay() {
+  ui::DisplayConfigurator::GetInstance()->DisableVirtualDisplay();
+}
+
+}  // namespace
+
+VirtualDisplayCapturer::VirtualDisplayCapturer(
+    scoped_refptr<base::SingleThreadTaskRunner> task_runner,
+    const DesktopMediaID& source)
+    : source_(source),
+      machine_(new AuraWindowCaptureMachine()),
+      device_task_runner_(task_runner) {
+  core_.reset(new ContentVideoCaptureDeviceCore(make_scoped_ptr(machine_)));
+  gfx::Screen::GetNativeScreen()->AddObserver(this);
+}
+
+VirtualDisplayCapturer::~VirtualDisplayCapturer() {
+  gfx::Screen::GetNativeScreen()->RemoveObserver(this);
+}
+
+// static
+media::VideoCaptureDevice* VirtualDisplayCapturer::Create(
+    scoped_refptr<base::SingleThreadTaskRunner> task_runner,
+    const DesktopMediaID& source) {
+  DCHECK(base::SysInfo::IsRunningOnChromeOS());
+  return new VirtualDisplayCapturer(task_runner, source);
+}
+
+void VirtualDisplayCapturer::AllocateAndStart(
+    const media::VideoCaptureParams& params,
+    scoped_ptr<Client> client) {
+  BrowserThread::PostTask(
+      BrowserThread::UI, FROM_HERE,
+      base::Bind(&EnableVirtualDisplay, params.requested_format.frame_size));
+
+  params_ = params;
+  client_.swap(client);
+}
+
+void VirtualDisplayCapturer::StopAndDeAllocate() {
+  core_->StopAndDeAllocate();
+  BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
+                          base::Bind(&DisableVirtualDisplay));
+}
+
+// This will be called after the VirtualDisplayMonitor object has updated the
+// virtual display in the DesktopMediaID::AuraWindowRegistry.
+void VirtualDisplayCapturer::OnDisplayAdded(const gfx::Display& display) {
+  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
+
+  if (display.id() ==
+      ui::DisplayConfigurator::GetInstance()->GetVirtualDisplayId()) {
+    aura::Window* window = DesktopMediaID::GetAuraWindowById(source_);
+    machine_->SetWindow(window);
+    gfx::Screen::GetNativeScreen()->RemoveObserver(this);
+    // Safe to use base::Unretained here as StopAndDeAllocate must be called
+    // before destroying |core_|.
+    device_task_runner_->PostTask(
+        FROM_HERE, base::Bind(&ContentVideoCaptureDeviceCore::AllocateAndStart,
+                              base::Unretained(core_.get()), params_,
+                              base::Passed(client_.Pass())));
+  }
+}
+
+}  // namespace content