Add 64-bit version of BitBuffer::ReadBits

Bug: webrtc:11933
Change-Id: Ie935192d2c81d7c24b83561711d59a7eff53db04
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/215966
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Björn Terelius <terelius@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#33997}
diff --git a/rtc_base/bit_buffer.h b/rtc_base/bit_buffer.h
index de7bf02..045d369 100644
--- a/rtc_base/bit_buffer.h
+++ b/rtc_base/bit_buffer.h
@@ -45,11 +45,13 @@
   // Reads bit-sized values from the buffer. Returns false if there isn't enough
   // data left for the specified bit count.
   bool ReadBits(uint32_t* val, size_t bit_count);
+  bool ReadBits(uint64_t* val, size_t bit_count);
 
   // Peeks bit-sized values from the buffer. Returns false if there isn't enough
   // data left for the specified number of bits. Doesn't move the current
   // offset.
   bool PeekBits(uint32_t* val, size_t bit_count);
+  bool PeekBits(uint64_t* val, size_t bit_count);
 
   // Reads value in range [0, num_values - 1].
   // This encoding is similar to ReadBits(val, Ceil(Log2(num_values)),