Cache --whitelisted-extension-id in SimpleFeature.

extensions/common/features/simple_feature.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "extensions/common/features/simple_feature.h"
 
 #include <map>
 #include <vector>
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/debug/alias.h"
 #include "base/lazy_instance.h"
+#include "base/macros.h"
 #include "base/sha1.h"
 #include "base/stl_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "extensions/common/extension_api.h"
 #include "extensions/common/features/feature_provider.h"
 #include "extensions/common/switches.h"
 
 namespace extensions {
@@ skipping 313 matching lines @@
   if (IsIdInBlacklist(extension_id))
     return CreateAvailability(FOUND_IN_BLACKLIST, type);
 
   // TODO(benwells): don't grant all component extensions.
   // See http://crbug.com/370375 for more details.
   // Component extensions can access any feature.
   // NOTE: Deliberately does not match EXTERNAL_COMPONENT.
   if (component_extensions_auto_granted_ && location == Manifest::COMPONENT)
     return CreateAvailability(IS_AVAILABLE, type);
 
-  if (!whitelist_.empty()) {
-    if (!IsIdInWhitelist(extension_id)) {
-      // TODO(aa): This is gross. There should be a better way to test the
-      // whitelist.
-      base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
-      if (!command_line->HasSwitch(switches::kWhitelistedExtensionID))
-        return CreateAvailability(NOT_FOUND_IN_WHITELIST, type);
-
-      std::string whitelist_switch_value =
-          base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
-              switches::kWhitelistedExtensionID);
-      if (extension_id != whitelist_switch_value)
-        return CreateAvailability(NOT_FOUND_IN_WHITELIST, type);
-    }
+  if (!whitelist_.empty() && !IsIdInWhitelist(extension_id) &&
+      (whitelisted_extension_id().empty() ||

[tapted, 2015/03/31 04:46:07]

hm - two function calls isn't quite as nice.. 

If it's true that an empty extension ID might get here, then maybe instead of
whitelisted_extension_id() returning a string, have

bool IsWhitelistedByCommandLine(const std::string& extension_id);

That probably reads better regardless :/

[jackhou1, 2015/03/31 05:28:22]

Done.

+       extension_id != whitelisted_extension_id())) {
+    return CreateAvailability(NOT_FOUND_IN_WHITELIST, type);
   }
 
   if (!MatchesManifestLocation(location))
     return CreateAvailability(INVALID_LOCATION, type);
 
   if (!platforms_.empty() && !ContainsKey(platforms_, platform))
     return CreateAvailability(INVALID_PLATFORM, type);
 
   if (min_manifest_version_ != 0 && manifest_version < min_manifest_version_)
     return CreateAvailability(INVALID_MIN_MANIFEST_VERSION, type);
@@ skipping 205 matching lines @@
         ExtensionAPI::GetSharedInstance()->GetFeatureDependency(dep_name);
     if (!dependency)
       return CreateAvailability(NOT_PRESENT);
     Availability dependency_availability = checker.Run(dependency);
     if (!dependency_availability.is_available())
       return dependency_availability;
   }
   return CreateAvailability(IS_AVAILABLE);
 }
 
+// static
+const std::string& SimpleFeature::whitelisted_extension_id() {
+  CR_DEFINE_STATIC_LOCAL(
+      std::string, whitelisted_extension_id,
+      (base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
+          switches::kWhitelistedExtensionID)));
+  return whitelisted_extension_id;
+}
+
 }  // namespace extensions