Fix case-sensitivity problems in extension content verification

extensions/browser/content_hash_reader.cc

Index: extensions/browser/content_hash_reader.cc
diff --git a/extensions/browser/content_hash_reader.cc b/extensions/browser/content_hash_reader.cc
index 76fb3e2941b08d932ff26a03b955782ff556825b..76c7e606126e5d71d82cfe220123c77edaccf261 100644
--- a/extensions/browser/content_hash_reader.cc
+++ b/extensions/browser/content_hash_reader.cc
@@ -85,14 +85,9 @@ bool ContentHashReader::Init() {
       block_size_ % crypto::kSHA256Length != 0)
     return false;
 
-  const std::string* expected_root =
-      verified_contents_->GetTreeHashRoot(relative_path_);
-  if (!expected_root)
-    return false;
-
   std::string root =
       ComputeTreeHashRoot(hashes_, block_size_ / crypto::kSHA256Length);
-  if (*expected_root != root)
+  if (!verified_contents_->TreeHashRootEquals(relative_path_, root))
     return false;
 
   status_ = SUCCESS;