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

gpu/command_buffer/service/query_manager.h

Index: gpu/command_buffer/service/query_manager.h
diff --git a/gpu/command_buffer/service/query_manager.h b/gpu/command_buffer/service/query_manager.h
index d77982b897fc161867a23c50ef3013b91e5a3d73..447fb464fea708cf63c845dc372694e2f951fd54 100644
--- a/gpu/command_buffer/service/query_manager.h
+++ b/gpu/command_buffer/service/query_manager.h
@@ -61,7 +61,7 @@ class GPU_EXPORT QueryManager {
     virtual bool Begin() = 0;
 
     // Returns false if shared memory for sync is invalid.
-    virtual bool End(uint32 submit_count) = 0;
+    virtual bool End(int32 submit_count) = 0;
 
     // Returns false if shared memory for sync is invalid.
     virtual bool Process() = 0;
@@ -84,7 +84,7 @@ class GPU_EXPORT QueryManager {
     // Returns false if shared memory for sync is invalid.
     bool MarkAsCompleted(uint64 result);
 
-    void MarkAsPending(uint32 submit_count) {
+    void MarkAsPending(int32 submit_count) {
       DCHECK(!pending_);
       pending_ = true;
       submit_count_ = submit_count;
@@ -96,12 +96,12 @@ class GPU_EXPORT QueryManager {
     }
 
     // Returns false if shared memory for sync is invalid.
-    bool AddToPendingQueue(uint32 submit_count) {
+    bool AddToPendingQueue(int32 submit_count) {
       return manager_->AddPendingQuery(this, submit_count);
     }
 
     // Returns false if shared memory for sync is invalid.
-    bool AddToPendingTransferQueue(uint32 submit_count) {
+    bool AddToPendingTransferQueue(int32 submit_count) {
       return manager_->AddPendingTransferQuery(this, submit_count);
     }
 
@@ -113,7 +113,7 @@ class GPU_EXPORT QueryManager {
       manager_->EndQueryHelper(target);
     }
 
-    uint32 submit_count() const {
+    int32 submit_count() const {
       return submit_count_;
     }
 
@@ -135,7 +135,7 @@ class GPU_EXPORT QueryManager {
     uint32 shm_offset_;
 
     // Count to set process count do when completed.
-    uint32 submit_count_;
+    int32 submit_count_;
 
     // True if in the queue.
     bool pending_;
@@ -169,7 +169,7 @@ class GPU_EXPORT QueryManager {
   bool BeginQuery(Query* query);
 
   // Returns false if any query is pointing to invalid shared memory.
-  bool EndQuery(Query* query, uint32 submit_count);
+  bool EndQuery(Query* query, int32 submit_count);
 
   // Processes pending queries. Returns false if any queries are pointing
   // to invalid shared memory.
@@ -200,11 +200,11 @@ class GPU_EXPORT QueryManager {
 
   // Adds to queue of queries waiting for completion.
   // Returns false if any query is pointing to invalid shared memory.
-  bool AddPendingQuery(Query* query, uint32 submit_count);
+  bool AddPendingQuery(Query* query, int32 submit_count);
 
   // Adds to queue of transfer queries waiting for completion.
   // Returns false if any query is pointing to invalid shared memory.
-  bool AddPendingTransferQuery(Query* query, uint32 submit_count);
+  bool AddPendingTransferQuery(Query* query, int32 submit_count);
 
   // Removes a query from the queue of pending queries.
   // Returns false if any query is pointing to invalid shared memory.