Bug 1488971 Move logic for disabling screenshots out of the extension r=kmag,_6a68

Differential Revision: https://phabricator.services.mozilla.com/D5310

--HG--
extra : source : a8de31323a3b52d7f4d6abd9405ba64e2227a653
extra : intermediate-source : ef0c065ebe0fc1918816718d45dc7e2a42545b06
extra : histedit_source : 56ceab6060017e3c893a17f1cd9d885f97fb7c31%2Cb574ee4b673e9c7443d8318f147982fc07774a54

browser/base/content/test/performance/browser_preferences_usage.js

@@ -99,6 +99,15 @@ add_task(async function startup() {
       min: 7,
       max: 55,
     },
+
+    // Disabling screenshots in the default test profile triggers some
+    // work in the chrome registry that reads this pref.  This can be removed
+    // when bootstrapped extensions are gone, or even when screenshots
+    // moves away from bootstrap (bug 1422437)
+    "chrome.override_package.global": {
+      min: 0,
+      max: 50,
+    },
   };
 
   let startupRecorder = Cc["@mozilla.org/test/startuprecorder;1"].getService().wrappedJSObject;

browser/components/nsBrowserGlue.js

@@ -1401,6 +1401,22 @@ BrowserGlue.prototype = {
     Normandy.uninit();
   },
 
+  // Set up a listener to enable/disable the screenshots extension
+  // based on its preference.
+  _monitorScreenshotsPref() {
+    const PREF = "extensions.screenshots.disabled";
+    const ID = "screenshots@mozilla.org";
+    Services.prefs.addObserver(PREF, async () => {
+      let addon = await AddonManager.getAddonByID(ID);
+      let disabled = Services.prefs.getBoolPref(PREF, false);
+      if (disabled) {
+        await addon.disable({allowSystemAddons: true});
+      } else {
+        await addon.enable({allowSystemAddons: true});
+      }
+    });
+  },
+
   // All initial windows have opened.
   _onWindowsRestored: function BG__onWindowsRestored() {
     if (this._windowsWereRestored) {
@@ -1457,6 +1473,8 @@ BrowserGlue.prototype = {
     };
     this._idleService.addIdleObserver(
       this._lateTasksIdleObserver, LATE_TASKS_IDLE_TIME_SEC);
+
+    this._monitorScreenshotsPref();
   },
 
   /**

browser/extensions/screenshots/bootstrap.js

@@ -25,25 +25,6 @@ let appStartupPromise = new Promise((resolve, reject) => {
 });
 
 const prefs = Services.prefs;
-const prefObserver = {
-  register() {
-    prefs.addObserver(PREF_BRANCH, this, false); // eslint-disable-line mozilla/no-useless-parameters
-  },
-
-  unregister() {
-    prefs.removeObserver(PREF_BRANCH, this, false); // eslint-disable-line mozilla/no-useless-parameters
-  },
-
-  observe(aSubject, aTopic, aData) {
-    // aSubject is the nsIPrefBranch we're observing (after appropriate QI)
-    // aData is the name of the pref that's been changed (relative to aSubject)
-    if (aData === USER_DISABLE_PREF) {
-      // eslint-disable-next-line promise/catch-or-return
-      appStartupPromise = appStartupPromise.then(handleStartup);
-    }
-  }
-};
-
 
 const appStartupObserver = {
   register() {
@@ -119,6 +100,18 @@ const APP_SHUTDOWN = 2;
 let addonData, startupReason;
 
 function startup(data, reason) { // eslint-disable-line no-unused-vars
+  addonResourceURI = data.resourceURI;
+
+  if (Services.prefs.getBoolPref(USER_DISABLE_PREF, false)) {
+    AddonManager.getActiveAddons().then(result => {
+      let addon = result.addons.find(a => a.id == ADDON_ID);
+      if (addon) {
+        addon.disable({allowSystemAddons: true});
+      }
+    });
+    return;
+  }
+
   addonData = data;
   startupReason = reason;
   if (reason === APP_STARTUP) {
@@ -126,14 +119,11 @@ function startup(data, reason) { // eslint-disable-line no-unused-vars
   } else {
     appStartupDone();
   }
-  prefObserver.register();
-  addonResourceURI = data.resourceURI;
   // eslint-disable-next-line promise/catch-or-return
   appStartupPromise = appStartupPromise.then(handleStartup);
 }
 
 function shutdown(data, reason) { // eslint-disable-line no-unused-vars
-  prefObserver.unregister();
   const webExtension = LegacyExtensionsUtils.getEmbeddedExtensionFor({
     id: ADDON_ID,
     resourceURI: addonResourceURI
@@ -155,20 +145,14 @@ function getBoolPref(pref) {
   return prefs.getPrefType(pref) && prefs.getBoolPref(pref);
 }
 
-function shouldDisable() {
-  return getBoolPref(USER_DISABLE_PREF);
-}
-
 function handleStartup() {
   const webExtension = LegacyExtensionsUtils.getEmbeddedExtensionFor({
     id: ADDON_ID,
     resourceURI: addonResourceURI
   });
 
-  if (!shouldDisable() && !webExtension.started) {
+  if (!webExtension.started) {
     start(webExtension);
-  } else if (shouldDisable()) {
-    stop(webExtension, ADDON_DISABLE);
   }
 }
 

toolkit/mozapps/extensions/internal/XPIDatabase.jsm

@@ -579,7 +579,7 @@ class AddonInternal {
     }
   }
 
-  async setUserDisabled(val) {
+  async setUserDisabled(val, allowSystemAddons = false) {
     if (val == (this.userDisabled || this.softDisabled)) {
       return;
     }
@@ -587,7 +587,7 @@ class AddonInternal {
     if (this.inDatabase) {
       // System add-ons should not be user disabled, as there is no UI to
       // re-enable them.
-      if (this.location.isSystem) {
+      if (this.location.isSystem && !allowSystemAddons) {
         throw new Error(`Cannot disable system add-on ${this.id}`);
       }
       await XPIDatabase.updateAddonDisabledState(this, val);
@@ -980,12 +980,14 @@ AddonWrapper = class {
     return addon.softDisabled || addon.userDisabled;
   }
 
-  enable() {
-    return addonFor(this).setUserDisabled(false);
+  enable(options = {}) {
+    const {allowSystemAddons = false} = options;
+    return addonFor(this).setUserDisabled(false, allowSystemAddons);
   }
 
-  disable() {
-    return addonFor(this).setUserDisabled(true);
+  disable(options = {}) {
+    const {allowSystemAddons = false} = options;
+    return addonFor(this).setUserDisabled(true, allowSystemAddons);
   }
 
   set softDisabled(val) {