[Origin Trials] Support updates of disabled token list

chrome/common/origin_trials/chrome_origin_trial_policy.cc

Index: chrome/common/origin_trials/chrome_origin_trial_policy.cc
diff --git a/chrome/common/origin_trials/chrome_origin_trial_policy.cc b/chrome/common/origin_trials/chrome_origin_trial_policy.cc
index d23c0fe958baaba36e3824a50a390db6b38e6ba0..3dcc096bbb38394edc61ef0f59e08c65165dc82b 100644
--- a/chrome/common/origin_trials/chrome_origin_trial_policy.cc
+++ b/chrome/common/origin_trials/chrome_origin_trial_policy.cc
@@ -39,6 +39,10 @@ ChromeOriginTrialPolicy::ChromeOriginTrialPolicy()
       SetDisabledFeatures(command_line->GetSwitchValueASCII(
           switches::kOriginTrialDisabledFeatures));
     }
+    if (command_line->HasSwitch(switches::kOriginTrialDisabledTokens)) {
+      SetDisabledTokens(command_line->GetSwitchValueASCII(
+          switches::kOriginTrialDisabledTokens));
+    }
   }
 }
 
@@ -53,6 +57,11 @@ bool ChromeOriginTrialPolicy::IsFeatureDisabled(
   return disabled_features_.count(feature.as_string()) > 0;
 }
 
+bool ChromeOriginTrialPolicy::IsTokenDisabled(
+    base::StringPiece token_signature) const {
+  return disabled_tokens_.count(token_signature.as_string()) > 0;
+}
+
 bool ChromeOriginTrialPolicy::SetPublicKeyFromASCIIString(
     const std::string& ascii_public_key) {
   // Base64-decode the incoming string. Set the key if it is correctly formatted
@@ -76,3 +85,21 @@ bool ChromeOriginTrialPolicy::SetDisabledFeatures(
   disabled_features_.swap(new_disabled_features);
   return true;
 }
+
+bool ChromeOriginTrialPolicy::SetDisabledTokens(
+    const std::string& disabled_token_list) {
+  std::set<std::string> new_disabled_tokens;
+  const std::vector<std::string> tokens =
+      base::SplitString(disabled_token_list, "|", base::TRIM_WHITESPACE,
+                        base::SPLIT_WANT_NONEMPTY);
+  for (const std::string& ascii_token : tokens) {
+    std::string token_signature;
+    if (!base::Base64Decode(ascii_token, &token_signature))
+      continue;
+    if (token_signature.size() != 64)
+      continue;
+    new_disabled_tokens.insert(token_signature);
+  }
+  disabled_tokens_.swap(new_disabled_tokens);
+  return true;
+}