Add disabled origin trial feature list

chrome/common/origin_trials/origin_trial_key_manager.cc

 // Copyright (c) 2016 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 "chrome/common/origin_trials/origin_trial_key_manager.h"
 
 #include <stdint.h>
 
+#include <vector>
+
 #include "base/base64.h"
+#include "base/strings/string_split.h"
 
 // This is the default public key used for validating signatures.
 // TODO(iclelland): Provide a mechanism to allow for multiple signing keys.
 // https://crbug.com/584737
 static const uint8_t kDefaultPublicKey[] = {
     0x7c, 0xc4, 0xb8, 0x9a, 0x93, 0xba, 0x6e, 0xe2, 0xd0, 0xfd, 0x03,
     0x1d, 0xfb, 0x32, 0x66, 0xc7, 0x3b, 0x72, 0xfd, 0x54, 0x3a, 0x07,
     0x51, 0x14, 0x66, 0xaa, 0x02, 0x53, 0x4e, 0x33, 0xa1, 0x15,
 };
 
@@ skipping 11 matching lines @@
     return false;
   if (new_public_key.size() != 32)
     return false;
   public_key_.swap(new_public_key);
   return true;
 }
 
 base::StringPiece OriginTrialKeyManager::GetPublicKey() const {
   return base::StringPiece(public_key_);
 }
+
+bool OriginTrialKeyManager::SetDisabledFeatures(
+    const std::string& disabled_feature_list) {
+  std::vector<std::string> features =

[Sorin Jianu, 2016/06/07 17:20:24]

can be const.

[iclelland, 2016/06/08 13:37:56]

Done.

+      base::SplitString(disabled_feature_list, "|", base::TRIM_WHITESPACE,
+                        base::SPLIT_WANT_NONEMPTY);
+  for (std::string feature : features)

[Sorin Jianu, 2016/06/07 17:20:24]

maybe use ref to const or const auto& for the range loop.

[iclelland, 2016/06/08 13:37:56]

Done.

+    disabled_features_.insert(feature);

[chasej, 2016/06/07 15:51:31]

Is this intended to append to the existing set of disabled features? From the
SetXXX naming, I would expect this method to replace any existing contents.

[iclelland, 2016/06/08 13:37:56]

That's a good point. It should probably clear the original list, if any. I don't
see any reason to require it to retain that. Done.

+  return true;
+}
+
+bool OriginTrialKeyManager::IsFeatureDisabled(base::StringPiece feature) {
+  return disabled_features_.count(feature.as_string()) > 0;
+}