Add support for encrypted WebM files as defined in the RFC.

media/base/decrypt_config.cc

Index: media/base/decrypt_config.cc
diff --git a/media/base/decrypt_config.cc b/media/base/decrypt_config.cc
index 9ae5f195e5d4cfab2be9a45108b23d329d2732e4..7dca08c02b1a492c28389f9259c6436c6ecb13f1 100644
--- a/media/base/decrypt_config.cc
+++ b/media/base/decrypt_config.cc
@@ -8,9 +8,22 @@
 
 namespace media {
 
-DecryptConfig::DecryptConfig(const uint8* key_id, int key_id_size)
-    : key_id_size_(key_id_size) {
+DecryptConfig::DecryptConfig(const uint8* data_to_verify,
+                             int data_to_verify_size,
+                             const uint8* iv, int iv_size,
+                             const uint8* key_id, int key_id_size,
+                             int offset_to_data)
+    :  data_to_verify_size_(data_to_verify_size),
+       iv_size_(iv_size),
+       key_id_size_(key_id_size),
+       offset_to_data_(offset_to_data) {
+  CHECK_GE(data_to_verify_size, 0);
+  CHECK_GT(iv_size, 0);
   CHECK_GT(key_id_size, 0);
+  data_to_verify_.reset(new uint8[data_to_verify_size]);
+  memcpy(data_to_verify_.get(), data_to_verify, data_to_verify_size);
+  iv_.reset(new uint8[iv_size]);
+  memcpy(iv_.get(), iv, iv_size);
   key_id_.reset(new uint8[key_id_size]);
   memcpy(key_id_.get(), key_id, key_id_size);
 }