Add Support for WebM

Adds support for WebM to the CDM. Decryption remains untouched,
however the initialization data is passed differently for WebM.

Merge of https://widevine-internal-review.googlesource.com/#/c/9225/
from the widevine cdm repo.

Bug: 10638562
Change-Id: I7b8cf4888fa408af77cee103f768f5a7c8ffdc7e

libwvdrmengine/src/WVDrmFactory.cpp

@@ -9,6 +9,7 @@
 #include "WVDrmFactory.h"
 
 #include "utils/Errors.h"
+#include "wv_cdm_constants.h"
 #include "WVCDMSingleton.h"
 #include "WVDrmPlugin.h"
 #include "WVUUID.h"
@@ -24,8 +25,9 @@ bool WVDrmFactory::isCryptoSchemeSupported(const uint8_t uuid[16]) {
 }
 
 bool WVDrmFactory::isContentTypeSupported(const String8 &mimeType) {
-  // For now, only ISO-BMFF is supported, which has MIME-type video/mp4
-  return mimeType == "video/mp4";
+  // Support ISO-BMFF (video/mp4) and WebM (video/webm).
+  return mimeType == wvcdm::ISO_BMFF_MIME_TYPE.c_str() ||
+         mimeType == wvcdm::WEBM_MIME_TYPE.c_str();
 }
 
 status_t WVDrmFactory::createDrmPlugin(const uint8_t uuid[16],