Extensions: Consolidate extension id hashing / searching.

extensions/common/extension.cc

Index: extensions/common/extension.cc
diff --git a/extensions/common/extension.cc b/extensions/common/extension.cc
index b721406701d0732e6fd83eec12798d41024cb329..8572b0c42c8e6fa31797d3e148b901b9d1662848 100644
--- a/extensions/common/extension.cc
+++ b/extensions/common/extension.cc
@@ -11,6 +11,7 @@
 #include "base/i18n/rtl.h"
 #include "base/logging.h"
 #include "base/memory/singleton.h"
+#include "base/sha1.h"
 #include "base/stl_util.h"
 #include "base/strings/string16.h"
 #include "base/strings/string_number_conversions.h"
@@ -390,6 +391,12 @@ const std::string Extension::GetVersionForDisplay() const {
   return VersionString();
 }
 
+std::string Extension::HashedIdInHex() const {

[Yoyo Zhou, 2015/01/22 00:59:13]

Can this go in id_util.h instead of extension.h?

crx_file::id_util::HashedIdInHex(string id)

+  const std::string id_hash = base::SHA1HashString(id());
+  DCHECK_EQ(base::kSHA1Length, id_hash.length());
+  return base::HexEncode(id_hash.c_str(), id_hash.length());
+}
+
 void Extension::AddInstallWarning(const InstallWarning& new_warning) {
   install_warnings_.push_back(new_warning);
 }