Gracefully handle multiple Flush/Reset/Decode with same id

The DCHECKs don't trigger in release, and in any case it's a bit rude to have
the renderer crash on a plugin that did the wrong thing, so send an error
instead.

BUG=None
TEST=Pepper Flash


Review URL: http://codereview.chromium.org/7628025

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@96649 0039d316-1c4b-4281-b951-d872f2087c98

ppapi/proxy/ppb_video_decoder_proxy.cc

@@ -96,7 +96,8 @@ int32_t VideoDecoder::Decode(
   if (enter_buffer.failed())
     return PP_ERROR_BADRESOURCE;
 
-  SetBitstreamBufferCallback(bitstream_buffer->id, callback);
+  if (!SetBitstreamBufferCallback(bitstream_buffer->id, callback))
+    return PP_ERROR_BADARGUMENT;
 
   Buffer* ppb_buffer =
       static_cast<Buffer*>(enter_buffer.object());
@@ -127,7 +128,8 @@ void VideoDecoder::ReusePictureBuffer(int32_t picture_buffer_id) {
 }
 
 int32_t VideoDecoder::Flush(PP_CompletionCallback callback) {
-  SetFlushCallback(callback);
+  if (!SetFlushCallback(callback))
+    return PP_ERROR_INPROGRESS;
 
   FlushCommandBuffer();
   GetDispatcher()->Send(new PpapiHostMsg_PPBVideoDecoder_Flush(
@@ -136,7 +138,8 @@ int32_t VideoDecoder::Flush(PP_CompletionCallback callback) {
 }
 
 int32_t VideoDecoder::Reset(PP_CompletionCallback callback) {
-  SetResetCallback(callback);
+  if (!SetResetCallback(callback))
+    return PP_ERROR_INPROGRESS;
 
   FlushCommandBuffer();
   GetDispatcher()->Send(new PpapiHostMsg_PPBVideoDecoder_Reset(

ppapi/shared_impl/video_decoder_impl.cc

@@ -44,22 +44,26 @@ void VideoDecoderImpl::Destroy() {
   UnrefResource(context3d_id_);
 }
 
-void VideoDecoderImpl::SetFlushCallback(PP_CompletionCallback callback) {
+bool VideoDecoderImpl::SetFlushCallback(PP_CompletionCallback callback) {
   CHECK(callback.func);
-  DCHECK(!flush_callback_.func);
+  if (flush_callback_.func)
+    return false;
   flush_callback_ = callback;
+  return true;
 }
 
-void VideoDecoderImpl::SetResetCallback(PP_CompletionCallback callback) {
+bool VideoDecoderImpl::SetResetCallback(PP_CompletionCallback callback) {
   CHECK(callback.func);
-  DCHECK(!reset_callback_.func);
+  if (reset_callback_.func)
+    return false;
   reset_callback_ = callback;
+  return true;
 }
 
-void VideoDecoderImpl::SetBitstreamBufferCallback(
+bool VideoDecoderImpl::SetBitstreamBufferCallback(
     int32 bitstream_buffer_id, PP_CompletionCallback callback) {
-  CHECK(bitstream_buffer_callbacks_.insert(
-      std::make_pair(bitstream_buffer_id, callback)).second);
+  return bitstream_buffer_callbacks_.insert(
+      std::make_pair(bitstream_buffer_id, callback)).second;
 }
 
 void VideoDecoderImpl::RunFlushCallback(int32 result) {

ppapi/shared_impl/video_decoder_impl.h

@@ -44,9 +44,9 @@ class VideoDecoderImpl : public thunk::PPB_VideoDecoder_API {
       std::vector<PP_VideoConfigElement>* out_configs);
 
  protected:
-  void SetFlushCallback(PP_CompletionCallback callback);
-  void SetResetCallback(PP_CompletionCallback callback);
-  void SetBitstreamBufferCallback(
+  bool SetFlushCallback(PP_CompletionCallback callback);
+  bool SetResetCallback(PP_CompletionCallback callback);
+  bool SetBitstreamBufferCallback(
       int32 bitstream_buffer_id, PP_CompletionCallback callback);
 
   void RunFlushCallback(int32 result);

webkit/plugins/ppapi/ppb_video_decoder_impl.cc

@@ -104,7 +104,8 @@ int32_t PPB_VideoDecoder_Impl::Decode(
       bitstream_buffer->id,
       buffer->shared_memory()->handle(),
       static_cast<size_t>(bitstream_buffer->size));
-  SetBitstreamBufferCallback(bitstream_buffer->id, callback);
+  if (!SetBitstreamBufferCallback(bitstream_buffer->id, callback))
+    return PP_ERROR_BADARGUMENT;
 
   FlushCommandBuffer();
   platform_video_decoder_->Decode(decode_buffer);
@@ -143,7 +144,8 @@ int32_t PPB_VideoDecoder_Impl::Flush(PP_CompletionCallback callback) {
   if (!platform_video_decoder_)
     return PP_ERROR_BADRESOURCE;
 
-  SetFlushCallback(callback);
+  if (!SetFlushCallback(callback))
+    return PP_ERROR_INPROGRESS;
 
   FlushCommandBuffer();
   platform_video_decoder_->Flush();
@@ -154,7 +156,8 @@ int32_t PPB_VideoDecoder_Impl::Reset(PP_CompletionCallback callback) {
   if (!platform_video_decoder_)
     return PP_ERROR_BADRESOURCE;
 
-  SetResetCallback(callback);
+  if (!SetResetCallback(callback))
+    return PP_ERROR_INPROGRESS;
 
   FlushCommandBuffer();
   platform_video_decoder_->Reset();