gpu: Add GpuFence framework.

gpu/command_buffer/service/gles2_cmd_decoder_passthrough.cc

Index: gpu/command_buffer/service/gles2_cmd_decoder_passthrough.cc
diff --git a/gpu/command_buffer/service/gles2_cmd_decoder_passthrough.cc b/gpu/command_buffer/service/gles2_cmd_decoder_passthrough.cc
index c81e60f7e92767c69351b5ac3045e784faa34ace..3e1897ffe0b48b0fde255b20401d7e202884a53d 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder_passthrough.cc
+++ b/gpu/command_buffer/service/gles2_cmd_decoder_passthrough.cc
@@ -168,6 +168,8 @@ bool GLES2DecoderPassthroughImpl::Initialize(
 
   image_manager_.reset(new ImageManager());
 
+  fence_manager_.reset(new FenceManager());
+
   bind_generates_resource_ = group_->bind_generates_resource();
 
   resources_ = group_->passthrough_resources();
@@ -193,6 +195,11 @@ bool GLES2DecoderPassthroughImpl::Initialize(
 void GLES2DecoderPassthroughImpl::Destroy(bool have_context) {
   image_manager_.reset();
 
+  if (fence_manager_.get()) {
+    fence_manager_->Destroy(have_context);
+    fence_manager_.reset();
+  }
+
   DeleteServiceObjects(
       &framebuffer_id_map_, have_context,
       [](GLuint framebuffer) { glDeleteFramebuffersEXT(1, &framebuffer); });
@@ -418,6 +425,10 @@ gpu::gles2::ImageManager* GLES2DecoderPassthroughImpl::GetImageManager() {
   return image_manager_.get();
 }
 
+gpu::gles2::FenceManager* GLES2DecoderPassthroughImpl::GetFenceManager() {
+  return fence_manager_.get();
+}
+
 bool GLES2DecoderPassthroughImpl::HasPendingQueries() const {
   return false;
 }