Chrome OS: avoid suspending on lid close when casting is active.

ash/shell.cc

Index: ash/shell.cc
diff --git a/ash/shell.cc b/ash/shell.cc
index 532da3e7fd56a71f1e7faec89a07a28f571bab13..785bb6ff1a22c5a4e45ef754058fff1ee3cc9c09 100644
--- a/ash/shell.cc
+++ b/ash/shell.cc
@@ -583,6 +583,7 @@ Shell::Shell(ShellDelegate* delegate)
   // We can't do this with a root window listener because XI_HierarchyChanged
   // messages don't have a target window.
   base::MessagePumpX11::Current()->AddObserver(output_configurator());
+  MediaCaptureDevicesDispatcher::GetInstance()->AddObserver(this);
 #endif  // defined(OS_CHROMEOS)
 
 #if defined(OS_CHROMEOS)
@@ -710,6 +711,7 @@ Shell::~Shell() {
   base::MessagePumpX11::Current()->RemoveDispatcherForRootWindow(
       output_configurator());
   base::MessagePumpX11::Current()->RemoveObserver(output_configurator());
+  MediaCaptureDevicesDispatcher::GetInstance()->RemoveObserver(this);
   display_change_observer_.reset();
 #endif  // defined(OS_CHROMEOS)
 
@@ -1036,4 +1038,23 @@ void Shell::OnWindowActivated(aura::Window* gained_active,
     target_root_window_ = gained_active->GetRootWindow();
 }
 
+////////////////////////////////////////////////////////////////////////////////
+// Shell, MediaCaptureDevicesDispatcher::Observer implementation:
+
+void Shell::OnRequestUpdate(int render_process_id,
+                            int render_view_id,
+                            const content::MediaStreamDevice& device,
+                            const content::MediaRequestState state) {
+#if defined(OS_CHROMEOS) && defined(USE_X11)
+  if (device.type == content::MEDIA_TAB_VIDEO_CAPTURE ||
+      device.type == content::MEDIA_DESKTOP_VIDEO_CAPTURE) {
+    if (state == content::MEDIA_REQUEST_STATE_DONE) {
+      output_configurator_->OnScreenSharingChanged(true);
+    } else if (state == content::MEDIA_REQUEST_STATE_CLOSING) {
+      output_configurator_->OnScreenSharingChanged(false);
+    }
+  }
+#endif
+}
+
 }  // namespace ash