Add CDM video decoder.

ppapi/proxy/ppp_content_decryptor_private_proxy.cc

Index: ppapi/proxy/ppp_content_decryptor_private_proxy.cc
diff --git a/ppapi/proxy/ppp_content_decryptor_private_proxy.cc b/ppapi/proxy/ppp_content_decryptor_private_proxy.cc
index 29190afcd9ffe4292fa9bc447d7f9ec9168e6675..e04e4cbca2c5c6b4e69928e5c462bb5569435998 100644
--- a/ppapi/proxy/ppp_content_decryptor_private_proxy.cc
+++ b/ppapi/proxy/ppp_content_decryptor_private_proxy.cc
@@ -485,10 +485,14 @@ void PPP_ContentDecryptor_Private_Proxy::OnMsgDecryptAndDecode(
     const PPPDecryptor_Buffer& encrypted_buffer,
     const std::string& serialized_block_info) {
   if (ppp_decryptor_impl_) {
-    PP_Resource plugin_resource =
-        PPB_Buffer_Proxy::AddProxyResource(encrypted_buffer.resource,
-                                           encrypted_buffer.handle,
-                                           encrypted_buffer.size);
+    PP_Resource plugin_resource = 0;

[xhwang, 2012/10/19 07:12:40]

Since PP_Resource of 0 can happen if error happens, I feel our implementation
isn't robust. I wonder if we can add extra info in block info to indicate that
input or output is empty. Not needed for this CL at all, but want to start
discussion on this.

[Tom Finegan, 2012/10/20 00:57:17]

Discussion in progress offline, but I don't think we have to do that...

+    if (encrypted_buffer.size > 0) {
+      plugin_resource =
+          PPB_Buffer_Proxy::AddProxyResource(encrypted_buffer.resource,

[brettw, 2012/10/19 23:03:54]

If you don't hit this line I believe encrypted_buffer.resource will leak,
causing the resource object in the renderer to leak.

[Tom Finegan, 2012/10/20 00:57:17]

Changed this and the usage above to occur only when there's a non-zero
encrypted_buffer.resource.

+                                             encrypted_buffer.handle,
+                                             encrypted_buffer.size);
+    }
+
     PP_EncryptedBlockInfo block_info;
     if (!DeserializeBlockInfo(serialized_block_info, &block_info))
       return;

[brettw, 2012/10/19 23:03:54]

If you hit this the plugin_resource will leak

[Tom Finegan, 2012/10/20 00:57:17]

Done. Thanks! This part now happens before we do anything with the resource.
Hopefully it's enough to avoid the problem, anyway.