Content verification: Don't fail on non-existence.

extensions/browser/content_hash_reader.h

Index: extensions/browser/content_hash_reader.h
diff --git a/extensions/browser/content_hash_reader.h b/extensions/browser/content_hash_reader.h
index cc2ea38b925bbdd99a873ceb1dd9edefe2ce2aa9..516897b5d37b4f5d215dcac39e94bbe60d093ec1 100644
--- a/extensions/browser/content_hash_reader.h
+++ b/extensions/browser/content_hash_reader.h
@@ -40,11 +40,15 @@ class ContentHashReader : public base::RefCountedThreadSafe<ContentHashReader> {
   // should likely be discarded.
   bool Init();
 
+  // Indicates whether the content in question exists in the local extension
+  // installation. This may be |false| if Init fails.
+  bool content_exists() const { return content_exists_; }
+
   // These return whether we found valid verified_contents.json /
   // computed_hashes.json files respectively. Note that both of these can be
   // true but we still didn't find an entry for |relative_path_| in them.
-  bool have_verified_contents() { return have_verified_contents_; }
-  bool have_computed_hashes() { return have_computed_hashes_; }
+  bool have_verified_contents() const { return have_verified_contents_; }
+  bool have_computed_hashes() const { return have_computed_hashes_; }
 
   // Return the number of blocks and block size, respectively. Only valid after
   // calling Init().
@@ -69,6 +73,8 @@ class ContentHashReader : public base::RefCountedThreadSafe<ContentHashReader> {
 
   InitStatus status_;
 
+  bool content_exists_;
+
   bool have_verified_contents_;
   bool have_computed_hashes_;