From 0faecc91b56d4e249b4ae7b210438fbd2ecf01cf Mon Sep 17 00:00:00 2001
From: Emma Malysz <emalysz@mozilla.com>
Date: Wed, 18 Mar 2020 22:33:01 +0000
Subject: [PATCH] Bug 1522930, delay GMP initialization until after first point
 to improve perceived performance. r=mconley

Differential Revision: https://phabricator.services.mozilla.com/D67165

--HG--
extra : moz-landing-system : lando
---
 .../extensions/internal/GMPProvider.jsm       | 33 +++++++++++++------
 .../test/xpcshell/test_gmpProvider.js         |  5 +++
 2 files changed, 28 insertions(+), 10 deletions(-)

diff --git a/toolkit/mozapps/extensions/internal/GMPProvider.jsm b/toolkit/mozapps/extensions/internal/GMPProvider.jsm
index 9973edf04cd7..45cdd33d52c2 100644
--- a/toolkit/mozapps/extensions/internal/GMPProvider.jsm
+++ b/toolkit/mozapps/extensions/internal/GMPProvider.jsm
@@ -48,6 +48,8 @@ const NS_GRE_DIR = "GreD";
 const CLEARKEY_PLUGIN_ID = "gmp-clearkey";
 const CLEARKEY_VERSION = "0.1";
 
+const FIRST_CONTENT_PROCESS_TOPIC = "ipc:first-content-process-created";
+
 const GMP_LICENSE_INFO = "gmp_license_info";
 const GMP_PRIVACY_INFO = "gmp_privacy_info";
 const GMP_LEARN_MORE = "learn_more_label";
@@ -880,15 +882,26 @@ var GMPProvider = {
       }
     }
   },
+
+  observe(subject, topic, data) {
+    if (topic == FIRST_CONTENT_PROCESS_TOPIC) {
+      AddonManagerPrivate.registerProvider(GMPProvider, [
+        new AddonManagerPrivate.AddonType(
+          "plugin",
+          URI_EXTENSION_STRINGS,
+          "type.plugin.name",
+          AddonManager.VIEW_TYPE_LIST,
+          6000,
+          AddonManager.TYPE_SUPPORTS_ASK_TO_ACTIVATE
+        ),
+      ]);
+      Services.obs.removeObserver(this, FIRST_CONTENT_PROCESS_TOPIC);
+    }
+  },
+
+  addObserver() {
+    Services.obs.addObserver(this, FIRST_CONTENT_PROCESS_TOPIC);
+  },
 };
 
-AddonManagerPrivate.registerProvider(GMPProvider, [
-  new AddonManagerPrivate.AddonType(
-    "plugin",
-    URI_EXTENSION_STRINGS,
-    "type.plugin.name",
-    AddonManager.VIEW_TYPE_LIST,
-    6000,
-    AddonManager.TYPE_SUPPORTS_ASK_TO_ACTIVATE
-  ),
-]);
+GMPProvider.addObserver();
diff --git a/toolkit/mozapps/extensions/test/xpcshell/test_gmpProvider.js b/toolkit/mozapps/extensions/test/xpcshell/test_gmpProvider.js
index a017a22c1c37..d27cb5f571c1 100644
--- a/toolkit/mozapps/extensions/test/xpcshell/test_gmpProvider.js
+++ b/toolkit/mozapps/extensions/test/xpcshell/test_gmpProvider.js
@@ -58,6 +58,11 @@ MockGMPInstallManager.prototype = {
 
 add_task(async function setup() {
   createAppInfo("xpcshell@tests.mozilla.org", "XPCShell", "1", "1.9.2");
+
+  // The GMPProvider does not register until the first content process
+  // is launched, so we simulate that by firing this notification.
+  Services.obs.notifyObservers(null, "ipc:first-content-process-created");
+
   await promiseStartupManager();
 
   gPrefs.setBoolPref(GMPScope.GMPPrefs.KEY_LOGGING_DUMP, true);