From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Shelley Vohr <shelley.vohr@gmail.com>
Date: Mon, 16 Aug 2021 17:55:32 +0200
Subject: fix: media key usage with globalShortcuts

This patch enables media keys to work properly with Electron's globalShortcut
module. Chromium's default usage of RemoteCommandCenterDelegate on macOS falls
down into MPRemoteCommandCenter, which makes it such that an app will not
receive remote control events until it begins playing audio. This runs
counter to the design of globalShortcuts, and so we need to instead
use `ui::MediaKeysListener`.

diff --git a/chrome/browser/extensions/global_shortcut_listener.cc b/chrome/browser/extensions/global_shortcut_listener.cc
index 245f714c853e691ec359a30168559d5c1f98e6cf..d1088a00e5f94aa73f7b24a6eda494ff20085d08 100644
--- a/chrome/browser/extensions/global_shortcut_listener.cc
+++ b/chrome/browser/extensions/global_shortcut_listener.cc
@@ -8,6 +8,7 @@
 #include "base/not_fatal_until.h"
 #include "base/notreached.h"
 #include "content/public/browser/browser_thread.h"
+#include "content/public/browser/media_keys_listener_manager.h"
 #include "ui/base/accelerators/accelerator.h"
 
 using content::BrowserThread;
@@ -67,6 +68,22 @@ void GlobalShortcutListener::UnregisterAccelerator(
     StopListening();
 }
 
+// static
+void GlobalShortcutListener::SetShouldUseInternalMediaKeyHandling(bool should_use) {
+  if (content::MediaKeysListenerManager::
+            IsMediaKeysListenerManagerEnabled()) {
+    content::MediaKeysListenerManager* media_keys_listener_manager =
+        content::MediaKeysListenerManager::GetInstance();
+    DCHECK(media_keys_listener_manager);
+
+    if (should_use) {
+      media_keys_listener_manager->EnableInternalMediaKeyHandling();
+    } else {
+      media_keys_listener_manager->DisableInternalMediaKeyHandling();
+    }
+  }
+}
+
 void GlobalShortcutListener::UnregisterAccelerators(Observer* observer) {
   CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   if (IsShortcutHandlingSuspended())
diff --git a/chrome/browser/extensions/global_shortcut_listener.h b/chrome/browser/extensions/global_shortcut_listener.h
index 06e65da05a218a8ecc641bbd749ace2b0832ce72..370dfdc9579a9e6b3a6bdc6f4526650a32f53b55 100644
--- a/chrome/browser/extensions/global_shortcut_listener.h
+++ b/chrome/browser/extensions/global_shortcut_listener.h
@@ -34,6 +34,8 @@ class GlobalShortcutListener {
 
   static GlobalShortcutListener* GetInstance();
 
+  static void SetShouldUseInternalMediaKeyHandling(bool should_use);
+
   // Register an observer for when a certain |accelerator| is struck. Returns
   // true if register successfully, or false if 1) the specificied |accelerator|
   // has been registered by another caller or other native applications, or
diff --git a/content/browser/media/media_keys_listener_manager_impl.cc b/content/browser/media/media_keys_listener_manager_impl.cc
index 2a84784fd3d759603a0dde5f6a7c94f4d0679147..b5616f8d09dd6471f8324f67b8261b0a4393d155 100644
--- a/content/browser/media/media_keys_listener_manager_impl.cc
+++ b/content/browser/media/media_keys_listener_manager_impl.cc
@@ -88,7 +88,11 @@ bool MediaKeysListenerManagerImpl::StartWatchingMediaKey(
       CanActiveMediaSessionControllerReceiveEvents();
 
   // Tell the underlying MediaKeysListener to listen for the key.
-  if (should_start_watching && media_keys_listener_ &&
+  if (
+#if BUILDFLAG(IS_MAC)
+      !media_key_handling_enabled_ &&
+#endif  // BUILDFLAG(IS_MAC)
+      should_start_watching && media_keys_listener_ &&
       !media_keys_listener_->StartWatchingMediaKey(key_code)) {
     return false;
   }
@@ -362,6 +366,20 @@ void MediaKeysListenerManagerImpl::StartListeningForMediaKeysIfNecessary() {
         this, ui::MediaKeysListener::Scope::kGlobal);
     DCHECK(media_keys_listener_);
   }
+
+#if BUILDFLAG(IS_MAC)
+  // Chromium's implementation of SystemMediaControls falls
+  // down into MPRemoteCommandCenter, which makes it such that an app will not
+  // will not receive remote control events until it begins playing audio.
+  // If there's not already a MediaKeysListener instance, create one so
+  // that globalShortcuts work correctly.
+  if (!media_keys_listener_) {
+    media_keys_listener_ = ui::MediaKeysListener::Create(
+        this, ui::MediaKeysListener::Scope::kGlobal);
+    DCHECK(media_keys_listener_);
+  }
+#endif
+
   EnsureAuxiliaryServices();
 }