Fix channel check for fatal error suppression.

extensions/common/extension_api.cc

 // Copyright 2013 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/extension_api.h"
 
 #include <algorithm>
 #include <string>
 #include <vector>
 
@@ skipping 249 matching lines @@
       return true;
   }
   return false;
 }
 
 Feature::Availability ExtensionAPI::IsAvailable(const std::string& full_name,
                                                 const Extension* extension,
                                                 Feature::Context context,
                                                 const GURL& url) {
   Feature* feature = GetFeatureDependency(full_name);
-  CHECK(feature) << full_name;
+  if (!feature) {
+    return Feature::CreateAvailability(Feature::NOT_PRESENT,
+        std::string("Unknown feature: ") + full_name);
+  }
   return IsAvailable(*feature, extension, context, url);
 }
 
 Feature::Availability ExtensionAPI::IsAvailable(const Feature& feature,
                                                 const Extension* extension,
                                                 Feature::Context context,
                                                 const GURL& url) {
   Feature::Availability availability =
       feature.IsAvailableToContext(extension, context, url);
   if (!availability.is_available())
@@ skipping 103 matching lines @@
       break;
 
     api_name_candidate = api_name_candidate.substr(0, last_dot_index);
   }
 
   *child_name = "";
   return std::string();
 }
 
 }  // namespace extensions