Implemented new fence syncs which replaces the old sync points.

ppapi/proxy/ppapi_command_buffer_proxy.cc

Index: ppapi/proxy/ppapi_command_buffer_proxy.cc
diff --git a/ppapi/proxy/ppapi_command_buffer_proxy.cc b/ppapi/proxy/ppapi_command_buffer_proxy.cc
index c430c784d167347e85536a6ca85d8b373fab2c3d..b7676dbcd3a3bb2207526fc30e09860c8d47bc4b 100644
--- a/ppapi/proxy/ppapi_command_buffer_proxy.cc
+++ b/ppapi/proxy/ppapi_command_buffer_proxy.cc
@@ -22,7 +22,10 @@ PpapiCommandBufferProxy::PpapiCommandBufferProxy(
     : command_buffer_id_(command_buffer_id),
       capabilities_(capabilities),
       resource_(resource),
-      dispatcher_(dispatcher) {
+      dispatcher_(dispatcher),
+      next_fence_sync_release_(1),
+      pending_fence_sync_release_(0),
+      flushed_fence_sync_release_(0) {
   shared_state_shm_.reset(
       new base::SharedMemory(shared_state.shmem(), false));
   shared_state_shm_->Map(shared_state.size());
@@ -56,18 +59,23 @@ void PpapiCommandBufferProxy::Flush(int32 put_offset) {
 
   OrderingBarrier(put_offset);
   FlushInternal();
+  flushed_fence_sync_release_ = next_fence_sync_release_ - 1;
 }
 
 void PpapiCommandBufferProxy::OrderingBarrier(int32 put_offset) {
   if (last_state_.error != gpu::error::kNoError)
     return;
 
-  if (flush_info_->flush_pending && flush_info_->resource != resource_)
+  if (flush_info_->flush_pending && flush_info_->resource != resource_) {
+    DCHECK(pending_fence_sync_release_ > flushed_fence_sync_release_);
     FlushInternal();
+    flushed_fence_sync_release_ = pending_fence_sync_release_;
+  }
 
   flush_info_->flush_pending = true;
   flush_info_->resource = resource_;
   flush_info_->put_offset = put_offset;
+  pending_fence_sync_release_ = next_fence_sync_release_ - 1;
 }
 
 void PpapiCommandBufferProxy::WaitForTokenInRange(int32 start, int32 end) {
@@ -187,6 +195,18 @@ uint64_t PpapiCommandBufferProxy::GetCommandBufferID() const {
   return command_buffer_id_;
 }
 
+uint32_t PpapiCommandBufferProxy::GenerateFenceSyncRelease() {
+  return next_fence_sync_release_++;
+}
+
+bool PpapiCommandBufferProxy::IsFenceSyncRelease(uint32_t release) {
+  return release != 0 && release < next_fence_sync_release_;
+}
+
+bool PpapiCommandBufferProxy::IsFenceSyncFlushed(uint32_t release) {

[piman, 2015/09/26 00:09:51]

Same as GpuChannelHost, you need to FlushInternal if a flush is pending.

[David Yen, 2015/09/28 17:38:18]

Same as previous comment, I would rather rely on them flushing. I have moved the
pending/flushed assignments around to FlushInternal() though, makes it a bit
easier to understand.

+  return release <= flushed_fence_sync_release_;
+}
+
 uint32 PpapiCommandBufferProxy::InsertSyncPoint() {
   uint32 sync_point = 0;
   if (last_state_.error == gpu::error::kNoError) {