Change WebM parser to treat IVs from encrypted WebM as raw data.

media/webm/webm_cluster_parser.cc

Index: media/webm/webm_cluster_parser.cc
diff --git a/media/webm/webm_cluster_parser.cc b/media/webm/webm_cluster_parser.cc
index fb1c69b874739719169085cbdcf4278862e95a61..6d9ac50b4861db0756f3f715538fa756dc5bad95 100644
--- a/media/webm/webm_cluster_parser.cc
+++ b/media/webm/webm_cluster_parser.cc
@@ -17,9 +17,9 @@ namespace media {
 // Generates a 16 byte CTR counter block. The CTR counter block format is a
 // CTR IV appended with a CTR block counter. |iv| is an 8 byte CTR IV.
 // Returns a string of kDecryptionKeySize bytes.
-static std::string GenerateCounterBlock(uint64 iv) {
-  std::string counter_block(reinterpret_cast<char*>(&iv), sizeof(iv));
-  counter_block.append(DecryptConfig::kDecryptionKeySize - sizeof(iv), 0);
+static std::string GenerateCounterBlock(const std::string& iv) {
+  std::string counter_block(iv);
+  counter_block.append(DecryptConfig::kDecryptionKeySize - kWebMIvSize, 0);
   return counter_block;
 }
 
@@ -237,10 +237,10 @@ bool WebMClusterParser::OnBlock(int track_num, int timecode,
     std::string counter_block;
 
     if (signal_byte & kWebMFlagEncryptedFrame) {
-      uint64 network_iv;
-      memcpy(&network_iv, data + data_offset, sizeof(network_iv));
-      data_offset += sizeof(network_iv);
-      counter_block = GenerateCounterBlock(base::NetToHost64(network_iv));
+      const std::string iv(reinterpret_cast<const char*>(data + data_offset),

[ddorwin, 2012/10/13 00:26:17]

nit: We create a string just to then copy it to another string. If we just
passed the pointer as before, we'd avoid a copy.

[fgalligan1, 2012/10/13 06:20:31]

Done.

+                           kWebMIvSize);
+      data_offset += kWebMIvSize;
+      counter_block = GenerateCounterBlock(iv);
     }
 
     // TODO(fgalligan): Revisit if DecryptConfig needs to be set on unencrypted