Update ActivityLog detection to use previous values, hrefs.

extensions/common/ad_injection_constants.h

 // 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.
 
 #ifndef EXTENSIONS_COMMON_AD_INJECTION_CONSTANTS_H_
 #define EXTENSIONS_COMMON_AD_INJECTION_CONSTANTS_H_
 
 #include <string>
 
 #include "base/basictypes.h"
 
 namespace extensions {
 namespace ad_injection_constants {
 
 // The keys used when serializing arguments to activity action APIs.
 namespace keys {
 
 extern const char kType[];
 extern const char kChildren[];
 extern const char kSrc[];
 extern const char kHref[];
 
 }  // namespace keys
 
 extern const char kHtmlIframeSrcApiName[];
 extern const char kHtmlEmbedSrcApiName[];
+extern const char kHtmlAnchorHrefApiName[];
 extern const char kAppendChildApiSuffix[];
 
 extern const size_t kMaximumChildrenToCheck;
 extern const size_t kMaximumDepthToCheck;
 
 // Returns true if the given |api| can potentially inject ads, and should
 // therefore be examined.
 bool ApiCanInjectAds(const std::string& api);
 
 }  // namespace ad_injection_constants
 }  // namespace extensions
 
 #endif  // EXTENSIONS_COMMON_AD_INJECTION_CONSTANTS_H_