Fix "unused variable" warnings.

chrome/browser/geolocation/geolocation_permission_context_extensions.cc

Index: chrome/browser/geolocation/geolocation_permission_context_extensions.cc
diff --git a/chrome/browser/geolocation/geolocation_permission_context_extensions.cc b/chrome/browser/geolocation/geolocation_permission_context_extensions.cc
index 12710968680035d4a3980d12a1f86388a48f58cc..58944f060001564470d1fa7f9352113cfbf626ae 100644
--- a/chrome/browser/geolocation/geolocation_permission_context_extensions.cc
+++ b/chrome/browser/geolocation/geolocation_permission_context_extensions.cc
@@ -22,19 +22,22 @@ using extensions::ExtensionRegistry;
 
 namespace {
 
-#if ENABLE_EXTENSIONS
+#if defined(ENABLE_EXTENSIONS)

[Peter Kasting, 2016/05/19 05:11:37]

I guess this worked before because the compiler treats undefined symbols as 0? 
In any case, using defined() matches every other instance in the codebase.

 void CallbackContentSettingWrapper(
     const base::Callback<void(ContentSetting)>& callback,
     bool allowed) {
   callback.Run(allowed ? CONTENT_SETTING_ALLOW : CONTENT_SETTING_BLOCK);
 }
-#endif // ENABLE_EXTENSIONS
+#endif  // defined(ENABLE_EXTENSIONS)
 
 }  // anonymous namespace
 
-GeolocationPermissionContextExtensions::
-GeolocationPermissionContextExtensions(Profile* profile)
-    : profile_(profile) {
+GeolocationPermissionContextExtensions::GeolocationPermissionContextExtensions(
+    Profile* profile)
+#if defined(ENABLE_EXTENSIONS)
+    : profile_(profile)
+#endif
+{
 }
 
 GeolocationPermissionContextExtensions::