Add unsigned 64-bit integer support to BigEndianReader and BigEndianWriter.

base/big_endian.cc

Index: base/big_endian.cc
diff --git a/base/big_endian.cc b/base/big_endian.cc
index fd9e7600ac17d79ce00cbbd7719a1331b5a5aa1b..9b69147a316e1f325e7e4304d8998750caca48f2 100644
--- a/base/big_endian.cc
+++ b/base/big_endian.cc
@@ -55,6 +55,10 @@ bool BigEndianReader::ReadU32(uint32* value) {
   return Read(value);
 }
 
+bool BigEndianReader::ReadU64(uint64* value) {
+  return Read(value);
+}
+
 BigEndianWriter::BigEndianWriter(char* buf, size_t len)
     : ptr_(buf), end_(ptr_ + len) {}
 
@@ -94,4 +98,8 @@ bool BigEndianWriter::WriteU32(uint32 value) {
   return Write(value);
 }
 
+bool BigEndianWriter::WriteU64(uint64 value) {
+  return Write(value);
+}
+
 }  // namespace base