Port Bug 1516044 - Add search hand-off pref to firefox.js r=andreio

lib/ActivityStream.jsm

@@ -193,10 +193,6 @@ const PREFS_CONFIG = new Map([
     title: "A comma-delimited list of search shortcuts that have previously been pinned",
     value: "",
   }],
-  ["improvesearch.handoffToAwesomebar", {
-    title: "Should the search box handoff to the Awesomebar?",
-    value: true,
-  }],
   ["asrouter.devtoolsEnabled", {
     title: "Are the asrouter devtools enabled?",
     value: false,

lib/PrefsFeed.jsm

@@ -93,6 +93,13 @@ this.PrefsFeed = class PrefsFeed {
     values["improvesearch.topSiteSearchShortcuts"] = searchTopSiteExperimentPrefValue;
     this._prefMap.set("improvesearch.topSiteSearchShortcuts", searchTopSiteExperimentPrefValue);
 
+    // Read the pref for search hand-off from firefox.js and store it
+    // in our interal list of prefs to watch
+    let handoffToAwesomebarPrefValue = Services.prefs.getBoolPref(
+      "browser.newtabpage.activity-stream.improvesearch.handoffToAwesomebar");
+    values["improvesearch.handoffToAwesomebar"] = handoffToAwesomebarPrefValue;
+    this._prefMap.set("improvesearch.handoffToAwesomebar", handoffToAwesomebarPrefValue);
+
     // Set the initial state of all prefs in redux
     this.store.dispatch(ac.BroadcastToContent({type: at.PREFS_INITIAL_VALUES, data: values}));