Bug 1282584: If we're not in the parent process, E10S must be on. r=jimm

MozReview-Commit-ID: LtWxnZAzxCl

--HG--
extra : rebase_source : bf09afcf3687ebfc387a874d2f83e8ba30913081

toolkit/xre/nsAppRunner.cpp

@@ -4878,6 +4878,11 @@ mozilla::BrowserTabsRemoteAutostart()
   }
   gBrowserTabsRemoteAutostartInitialized = true;
 
+  // If we're in the content process, we are running E10S.
+  if (XRE_IsContentProcess()) {
+    gBrowserTabsRemoteAutostart = true;
+    return gBrowserTabsRemoteAutostart;
+  }
 
   bool optInPref = Preferences::GetBool("browser.tabs.remote.autostart", false);
   bool trialPref = Preferences::GetBool("browser.tabs.remote.autostart.2", false);