Remove MOZ_B2G leftovers and some dead B2G-only components.

testing/marionette/assert.js

@@ -15,7 +15,7 @@ Cu.import("chrome://marionette/content/error.js");
 this.EXPORTED_SYMBOLS = ["assert"];
 
 const isFennec = () => AppConstants.platform == "android";
-const isB2G = () => AppConstants.MOZ_B2G;
+const isB2G = () => false;
 const isFirefox = () => Services.appinfo.name == "Firefox";
 
 /** Shorthands for common assertions made in Marionette. */

testing/specialpowers/content/specialpowersAPI.js

@@ -1529,11 +1529,7 @@ SpecialPowersAPI.prototype = {
   },
 
   get isB2G() {
-#ifdef MOZ_B2G
-    return true;
-#else
     return false;
-#endif
   },
 
   addSystemEventListener: function(target, type, listener, useCapture) {

testing/testsuite-targets.mk

@@ -18,10 +18,6 @@ ifneq (1_WINNT,$(MOZ_PGO)_$(OS_ARCH))
 BUILD_GTEST=1
 endif
 
-ifdef MOZ_B2G
-BUILD_GTEST=
-endif
-
 ifndef MOZ_PHOENIX
 BUILD_GTEST=
 endif