IndexedDB: Fixed support for empty blobs.

storage/common/data_element.h

 // 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.
 
 #ifndef STORAGE_COMMON_DATA_ELEMENT_H_
 #define STORAGE_COMMON_DATA_ELEMENT_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 15 matching lines @@
     TYPE_BYTES,
     TYPE_FILE,
     TYPE_BLOB,
     TYPE_FILE_FILESYSTEM,
   };
 
   DataElement();
   ~DataElement();
 
   Type type() const { return type_; }
-  const char* bytes() const { return bytes_ ? bytes_ : &buf_[0]; }
+  const char* bytes() const {
+    if (length_)
+      return bytes_ ? bytes_ : &buf_[0];
+    else
+      return nullptr;
+  }
   const base::FilePath& path() const { return path_; }
   const GURL& filesystem_url() const { return filesystem_url_; }
   const std::string& blob_uuid() const { return blob_uuid_; }
   uint64 offset() const { return offset_; }
   uint64 length() const { return length_; }
   const base::Time& expected_modification_time() const {
     return expected_modification_time_;
   }
 
   // Sets TYPE_BYTES data. This copies the given data into the element.
@@ skipping 91 matching lines @@
 }
 
 inline bool operator!=(const DataElement& a, const DataElement& b) {
   return !(a == b);
 }
 #endif  // defined(UNIT_TEST)
 
 }  // namespace storage
 
 #endif  // STORAGE_COMMON_DATA_ELEMENT_H_