ui: Add ref-counting to GLFence class.

gpu/command_buffer/service/query_manager.cc

Index: gpu/command_buffer/service/query_manager.cc
diff --git a/gpu/command_buffer/service/query_manager.cc b/gpu/command_buffer/service/query_manager.cc
index a5071e335d7ad1cb9088f785168894d98293e995..4c10f77b0c778426c73e579d0ac4fffaa06a4f2d 100644
--- a/gpu/command_buffer/service/query_manager.cc
+++ b/gpu/command_buffer/service/query_manager.cc
@@ -479,7 +479,7 @@ class CommandsCompletedQuery : public QueryManager::Query {
   ~CommandsCompletedQuery() override;
 
  private:
-  std::unique_ptr<gl::GLFence> fence_;
+  scoped_refptr<gl::GLFence> fence_;
   base::TimeTicks begin_time_;
 };
 
@@ -508,7 +508,7 @@ bool CommandsCompletedQuery::End(base::subtle::Atomic32 submit_count) {
     fence_->ResetState();
   }
   else {
-    fence_.reset(gl::GLFence::Create());
+    fence_ = gl::GLFence::Create();
   }
   DCHECK(fence_);
   return AddToPendingQueue(submit_count);
@@ -532,7 +532,7 @@ bool CommandsCompletedQuery::Process(bool did_finish) {
 
 void CommandsCompletedQuery::Destroy(bool have_context) {
   if (have_context && !IsDeleted()) {
-    fence_.reset();
+    fence_ = nullptr;
     MarkAsDeleted();
   }
 }