Tighten up media::DecoderBuffer API contract for end of stream buffers (round 2).

webkit/plugins/ppapi/content_decryptor_delegate.cc

Index: webkit/plugins/ppapi/content_decryptor_delegate.cc
diff --git a/webkit/plugins/ppapi/content_decryptor_delegate.cc b/webkit/plugins/ppapi/content_decryptor_delegate.cc
index 069f367c6f47b8d2e3496372b09e7a259c90c311..e93bc93c7e2dbdef62e5f65e68c93172d43460b3 100644
--- a/webkit/plugins/ppapi/content_decryptor_delegate.cc
+++ b/webkit/plugins/ppapi/content_decryptor_delegate.cc
@@ -79,29 +79,29 @@ bool CopyStringToArray(const std::string& str, uint8 (&array)[array_size]) {
 }
 
 // Fills the |block_info| with information from |decrypt_config|, |timestamp|
-// and |request_id|. |decrypt_config| can be NULL if the block is not encrypted.
-// This is useful for end-of-stream blocks.
+// and |request_id|.
+//
 // Returns true if |block_info| is successfully filled. Returns false
 // otherwise.
-bool MakeEncryptedBlockInfo(int data_size,
-                            const media::DecryptConfig* decrypt_config,
-                            int64_t timestamp,
-                            uint32_t request_id,
-                            PP_EncryptedBlockInfo* block_info) {
-  DCHECK(block_info);
-
+static bool MakeEncryptedBlockInfo(
+    const scoped_refptr<media::DecoderBuffer>& encrypted_buffer,
+    uint32_t request_id,
+    PP_EncryptedBlockInfo* block_info) {
   // TODO(xhwang): Fix initialization of PP_EncryptedBlockInfo here and
   // anywhere else.
   memset(block_info, 0, sizeof(*block_info));
-
   block_info->tracking_info.request_id = request_id;
-  block_info->tracking_info.timestamp = timestamp;
 
-  if (!decrypt_config)
+  // EOS buffers need a request ID and nothing more.
+  if (encrypted_buffer->IsEndOfStream())
     return true;
 
-  DCHECK(data_size) << "DecryptConfig is set on an empty buffer";
-  block_info->data_size = data_size;
+  block_info->tracking_info.timestamp =
+      encrypted_buffer->GetTimestamp().InMicroseconds();
+  block_info->data_size = encrypted_buffer->GetDataSize();
+
+  const media::DecryptConfig* decrypt_config =
+      encrypted_buffer->GetDecryptConfig();
   block_info->data_offset = decrypt_config->data_offset();
 
   if (!CopyStringToArray(decrypt_config->key_id(), block_info->key_id) ||
@@ -365,11 +365,7 @@ bool ContentDecryptorDelegate::Decrypt(
 
   PP_EncryptedBlockInfo block_info = {};
   DCHECK(encrypted_buffer->GetDecryptConfig());
-  if (!MakeEncryptedBlockInfo(encrypted_buffer->GetDataSize(),
-                              encrypted_buffer->GetDecryptConfig(),
-                              encrypted_buffer->GetTimestamp().InMicroseconds(),
-                              request_id,
-                              &block_info)) {
+  if (!MakeEncryptedBlockInfo(encrypted_buffer, request_id, &block_info)) {
     return false;
   }
 
@@ -535,13 +531,13 @@ bool ContentDecryptorDelegate::DecryptAndDecodeAudio(
   // because there is only one pending audio decode request at any time.
   // This is enforced by the media pipeline.
   scoped_refptr<PPB_Buffer_Impl> encrypted_resource;
-  if (!MakeMediaBufferResource(media::Decryptor::kAudio,
+  if (!encrypted_buffer->IsEndOfStream() &&
+      !MakeMediaBufferResource(media::Decryptor::kAudio,
                                encrypted_buffer->GetData(),
                                encrypted_buffer->GetDataSize(),
                                &encrypted_resource)) {
     return false;
   }
-  ScopedPPResource pp_resource(encrypted_resource.get());
 
   // The resource should not be NULL for non-EOS buffer.
   if (!encrypted_buffer->IsEndOfStream() && !encrypted_resource)
@@ -551,12 +547,7 @@ bool ContentDecryptorDelegate::DecryptAndDecodeAudio(
   DVLOG(2) << "DecryptAndDecodeAudio() - request_id " << request_id;
 
   PP_EncryptedBlockInfo block_info = {};
-  if (!MakeEncryptedBlockInfo(
-      encrypted_buffer->GetDataSize(),
-      encrypted_buffer->GetDecryptConfig(),
-      encrypted_buffer->GetTimestamp().InMicroseconds(),
-      request_id,
-      &block_info)) {
+  if (!MakeEncryptedBlockInfo(encrypted_buffer, request_id, &block_info)) {
     return false;
   }
 
@@ -571,6 +562,7 @@ bool ContentDecryptorDelegate::DecryptAndDecodeAudio(
   pending_audio_decode_request_id_ = request_id;
   pending_audio_decode_cb_ = audio_decode_cb;
 
+  ScopedPPResource pp_resource(encrypted_resource.get());
   plugin_decryption_interface_->DecryptAndDecode(pp_instance_,
                                                  PP_DECRYPTORSTREAMTYPE_AUDIO,
                                                  pp_resource,
@@ -581,20 +573,17 @@ bool ContentDecryptorDelegate::DecryptAndDecodeAudio(
 bool ContentDecryptorDelegate::DecryptAndDecodeVideo(
     const scoped_refptr<media::DecoderBuffer>& encrypted_buffer,
     const media::Decryptor::VideoDecodeCB& video_decode_cb) {
-  // If |encrypted_buffer| is end-of-stream buffer, GetData() and GetDataSize()
-  // return NULL and 0 respectively. In that case, we'll just get a NULL
-  // resource.
   // |video_input_resource_| is not being used by the plugin now
   // because there is only one pending video decode request at any time.
   // This is enforced by the media pipeline.
   scoped_refptr<PPB_Buffer_Impl> encrypted_resource;
-  if (!MakeMediaBufferResource(media::Decryptor::kVideo,
+  if (!encrypted_buffer->IsEndOfStream() &&
+      !MakeMediaBufferResource(media::Decryptor::kVideo,
                                encrypted_buffer->GetData(),
                                encrypted_buffer->GetDataSize(),
                                &encrypted_resource)) {
     return false;
   }
-  ScopedPPResource pp_resource(encrypted_resource.get());
 
   // The resource should not be 0 for non-EOS buffer.
   if (!encrypted_buffer->IsEndOfStream() && !encrypted_resource)
@@ -606,12 +595,7 @@ bool ContentDecryptorDelegate::DecryptAndDecodeVideo(
       "eme", "ContentDecryptorDelegate::DecryptAndDecodeVideo", request_id);
 
   PP_EncryptedBlockInfo block_info = {};
-  if (!MakeEncryptedBlockInfo(
-      encrypted_buffer->GetDataSize(),
-      encrypted_buffer->GetDecryptConfig(),
-      encrypted_buffer->GetTimestamp().InMicroseconds(),
-      request_id,
-      &block_info)) {
+  if (!MakeEncryptedBlockInfo(encrypted_buffer, request_id, &block_info)) {
     return false;
   }
 
@@ -627,6 +611,7 @@ bool ContentDecryptorDelegate::DecryptAndDecodeVideo(
   pending_video_decode_cb_ = video_decode_cb;
 
   // TODO(tomfinegan): Need to get stream type from media stack.
+  ScopedPPResource pp_resource(encrypted_resource.get());
   plugin_decryption_interface_->DecryptAndDecode(pp_instance_,
                                                  PP_DECRYPTORSTREAMTYPE_VIDEO,
                                                  pp_resource,
@@ -984,13 +969,6 @@ bool ContentDecryptorDelegate::MakeMediaBufferResource(
   TRACE_EVENT0("eme", "ContentDecryptorDelegate::MakeMediaBufferResource");
 
   DCHECK(resource);
-
-  if (!data || !size) {
-    DCHECK(!data && !size);
-    resource = NULL;
-    return true;
-  }
-
   DCHECK(stream_type == media::Decryptor::kAudio ||
          stream_type == media::Decryptor::kVideo);
   scoped_refptr<PPB_Buffer_Impl>& media_resource =