gpu: Use explicit atomics instead of assuming that 32bit read/writes are atomic.

gpu/command_buffer/client/query_tracker.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef GPU_COMMAND_BUFFER_CLIENT_QUERY_TRACKER_H_
 #define GPU_COMMAND_BUFFER_CLIENT_QUERY_TRACKER_H_
 
 #include <GLES2/gl2.h>
 
 #include <deque>
@@ skipping 87 matching lines @@
       return info_.shm_id;
     }
 
     uint32 shm_offset() const {
       return info_.shm_offset;
     }
 
     void MarkAsActive() {
       state_ = kActive;
       ++submit_count_;
+      if (submit_count_ == INT_MAX)
+        submit_count_ = 1;
     }
 
     void MarkAsPending(int32 token) {
       token_ = token;
       state_ = kPending;
       flushed_ = false;
     }
 
-    uint32 submit_count() const {
+    int32 submit_count() const {
       return submit_count_;
     }
 
     int32 token() const {
       return token_;
     }
 
     bool NeverUsed() const {
       return state_ == kUninitialized;
     }
@@ skipping 10 matching lines @@
     void End(GLES2Implementation* gl);
 
    private:
     friend class QueryTracker;
     friend class QueryTrackerTest;
 
     GLuint id_;
     GLenum target_;
     QuerySyncManager::QueryInfo info_;
     State state_;
-    uint32 submit_count_;
+    int32 submit_count_;
     int32 token_;
     bool flushed_;
     uint64 client_begin_time_us_; // Only used for latency query target.
     uint32 result_;
   };
 
   QueryTracker(MappedMemoryManager* manager);
   ~QueryTracker();
 
   Query* CreateQuery(GLuint id, GLenum target);
@@ skipping 10 matching lines @@
   QueryList removed_queries_;
   QuerySyncManager query_sync_manager_;
 
   DISALLOW_COPY_AND_ASSIGN(QueryTracker);
 };
 
 }  // namespace gles2
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_CLIENT_QUERY_TRACKER_H_