MD Settings: FakeSettingsPrivate for tests

chrome/browser/resources/settings/prefs/prefs.js

Index: chrome/browser/resources/settings/prefs/prefs.js
diff --git a/chrome/browser/resources/settings/prefs/prefs.js b/chrome/browser/resources/settings/prefs/prefs.js
index d46ff88776ceb394d102f6c2f641427a904f0ea9..4d39adc5b7f3fa0cb384e7563d204654ff0a676b 100644
--- a/chrome/browser/resources/settings/prefs/prefs.js
+++ b/chrome/browser/resources/settings/prefs/prefs.js
@@ -267,22 +267,15 @@
       'prefs-changed': 'prefsChanged_',
     },
 
-    settingsApi_: chrome.settingsPrivate,
-
     initialize: function() {
       // Only initialize once (or after resetForTesting() is called).
       if (this.initialized_)
         return;
       this.initialized_ = true;
 
-      // Set window.mockApi to pass a custom settings API, i.e. for tests.
-      // TODO(michaelpg): don't use a global.
-      if (window.mockApi)
-        this.settingsApi_ = window.mockApi;
-
-      this.settingsApi_.onPrefsChanged.addListener(
+      chrome.settingsPrivate.onPrefsChanged.addListener(

[Dan Beam, 2015/11/17 23:01:15]

why are you [able to] undo this?

[michaelpg, 2015/11/17 23:51:51]

I don't like this because:
  * checking for a global sucks
  * grepping chrome.settingsPrivate.foo to check usage becomes ineffective
  * i don't think Closure can type-check the previous version because there's no
"type" for the API (I confirmed it wasn't checking usage of this.settingsApi_,
but IDK if it would be possible to tell Closure that this.settingsApi_ is an
"alias" for chrome.settingsPrivate)

As far as ability, this is done by the fake setting chrome.settingsPrivate to
itself.

           this.onSettingsPrivatePrefsChanged_.bind(this));
-      this.settingsApi_.getAllPrefs(
+      chrome.settingsPrivate.getAllPrefs(
           this.onSettingsPrivatePrefsFetched_.bind(this));
     },
 
@@ -308,7 +301,7 @@
       if (deepEqual(prefStoreValue, prefObj.value))
         return;
 
-      this.settingsApi_.setPref(
+      chrome.settingsPrivate.setPref(
           key,
           prefObj.value,
           /* pageId */ '',
@@ -348,7 +341,7 @@
 
       // Get the current pref value from chrome.settingsPrivate to ensure the
       // UI stays up to date.
-      this.settingsApi_.getPref(key, function(pref) {
+      chrome.settingsPrivate.getPref(key, function(pref) {
         this.updatePrefs_([pref]);
       }.bind(this));
     },