Add MetalayerMode to the palette.

chrome/browser/ui/ash/palette_delegate_chromeos.cc

 // Copyright 2016 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 "chrome/browser/ui/ash/palette_delegate_chromeos.h"
 
 #include "ash/accelerators/accelerator_controller_delegate_aura.h"
 #include "ash/aura/shell_port_classic.h"
 #include "ash/screenshot_delegate.h"
 #include "ash/shell.h"
@@ skipping 161 matching lines @@
   auto* screenshot_delegate = ash::ShellPortClassic::Get()
                                   ->accelerator_controller_delegate()
                                   ->screenshot_delegate();
   screenshot_delegate->HandleTakeScreenshotForAllRootWindows();
 }
 
 void PaletteDelegateChromeOS::TakePartialScreenshot(const base::Closure& done) {
   auto* screenshot_controller = ash::Shell::Get()->screenshot_controller();
 
   ash::ScreenshotDelegate* screenshot_delegate;
-  if (arc::ArcVoiceInteractionFrameworkService::IsVoiceInteractionEnabled() &&
-      arc::IsArcAllowedForProfile(profile_)) {
+  if (HasMetalayer()) {
     // This is an experimental mode. It will be either taken out or grow
     // into a separate tool next to "Capture region".
     if (!voice_interaction_screenshot_delegate_) {
       voice_interaction_screenshot_delegate_ =
           base::MakeUnique<VoiceInteractionScreenshotDelegate>();
     }
     screenshot_delegate = voice_interaction_screenshot_delegate_.get();
   } else {
     screenshot_delegate = ash::ShellPortClassic::Get()
                               ->accelerator_controller_delegate()
                               ->screenshot_delegate();
   }
 
   screenshot_controller->set_pen_events_only(true);
   screenshot_controller->StartPartialScreenshotSession(
       screenshot_delegate, false /* draw_overlay_immediately */);
   screenshot_controller->set_on_screenshot_session_done(
       base::Bind(&PaletteDelegateChromeOS::OnPartialScreenshotDone,
                  weak_factory_.GetWeakPtr(), done));
 }
 
 void PaletteDelegateChromeOS::CancelPartialScreenshot() {
   ash::Shell::Get()->screenshot_controller()->CancelScreenshotSession();
 }
 
+bool PaletteDelegateChromeOS::HasMetalayer() {
+  if (!arc::IsArcAllowedForProfile(profile_))

[Luis Héctor Chávez, 2017/04/19 15:48:29]

Don't we also want to check
arc::ArcVoiceInteractionFrameworkService::IsVoiceInteractionEnabled() here?

[Vladislav Kaznacheev, 2017/04/19 23:42:59]

ArcVoiceInteractionFrameworkService instantiation is guarded by this exact
condition. If this check is false, service below would be null.

+    return false;
+
+  arc::ArcVoiceInteractionFrameworkService* service =
+      arc::ArcServiceManager::Get()
+          ->GetService<arc::ArcVoiceInteractionFrameworkService>();
+  return service && service->IsReady();
+}
+
+void PaletteDelegateChromeOS::ShowMetalayer(const base::Closure& done) {
+  arc::ArcVoiceInteractionFrameworkService* service =

[Luis Héctor Chávez, 2017/04/19 15:48:29]

If the container dies just prior to this being called, |done| will never get
resolved and that would cause the palette to never be closed (IIUC). That sounds
racy.

How about you get rid of the arc::ArcVoiceInteractionFrameworkService::IsReady()
check in HasMetalayer() altogether, and instead immediately resolve the callback
(in arc::ArcVoiceInteractionFrameworkService) when it's not ready?

Maybe also have |done| be a base::Callback<void(bool)> to be able to notify the
caller that the operation failed? (not so sure about this, it seems that the
caller does not care about it, only that it's gone).

[Vladislav Kaznacheev, 2017/04/19 23:42:59]

Replaced DCHECK with closure resolution and return. 
 
The purpose of IsReady is to propagate through a delegate to the palette code
which will not surface the Metalayer tool if this call returns false. I have
renamed it to HasMetalayer and instead of looking at the flag (now removed)
it is trying to get hold the framework instance.
For the palette UI it does not really matter if the Metalayer failed to
open or closed soon after opening. I will make sure that on the container
calls OnMetalayerComplete if it sees that Metalayer has not started.

+      arc::ArcServiceManager::Get()
+          ->GetService<arc::ArcVoiceInteractionFrameworkService>();
+  DCHECK(service);
+  service->ShowMetalayer(done);
+}
+
+void PaletteDelegateChromeOS::HideMetalayer() {
+  arc::ArcVoiceInteractionFrameworkService* service =
+      arc::ArcServiceManager::Get()
+          ->GetService<arc::ArcVoiceInteractionFrameworkService>();
+  DCHECK(service);
+  service->HideMetalayer();
+}
+
 }  // namespace chromeos