[Extensions] Clean up renderer channel-related code

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 <algorithm>
 #include <map>
 #include <utility>
 #include <vector>
@@ skipping 409 matching lines @@
     return CreateAvailability(INVALID_MIN_MANIFEST_VERSION, type);
 
   if (max_manifest_version_ != 0 && manifest_version > max_manifest_version_)
     return CreateAvailability(INVALID_MAX_MANIFEST_VERSION, type);
 
   if (!command_line_switch_.empty() &&
       !IsCommandLineSwitchEnabled(command_line_switch_)) {
     return CreateAvailability(MISSING_COMMAND_LINE_SWITCH, type);
   }
 
-  if (channel_ && check_channel_ && *channel_ < GetCurrentChannel())
+  if (channel_ && *channel_ < GetCurrentChannel())
     return CreateAvailability(UNSUPPORTED_CHANNEL, *channel_);
 
   return CheckDependencies(base::Bind(&IsAvailableToManifestForBind,
                                       extension_id,
                                       type,
                                       location,
                                       manifest_version,
                                       platform));
 }
 
@@ skipping 212 matching lines @@
 bool SimpleFeature::IsValidExtensionId(const std::string& extension_id) {
   // Belt-and-suspenders philosophy here. We should be pretty confident by this
   // point that we've validated the extension ID format, but in case something
   // slips through, we avoid a class of attack where creative ID manipulation
   // leads to hash collisions.
   // 128 bits / 4 = 32 mpdecimal characters
   return (extension_id.length() == 32);
 }
 
 }  // namespace extensions