gpu: Reuse transfer buffers more aggresively

gpu/command_buffer/client/query_tracker.h

Index: gpu/command_buffer/client/query_tracker.h
diff --git a/gpu/command_buffer/client/query_tracker.h b/gpu/command_buffer/client/query_tracker.h
index 9e7f501768b74a5bbfa4dccfb2bee6e153622dfa..ebb7856ad1cf5cd8fae2773a2897288784773ea6 100644
--- a/gpu/command_buffer/client/query_tracker.h
+++ b/gpu/command_buffer/client/query_tracker.h
@@ -102,6 +102,14 @@ class GLES2_IMPL_EXPORT QueryTracker {
       return info_.shm_offset;
     }
 
+    uint32 serial() const {
+      return serial_;
+    }
+
+    void set_serial(uint32 serial) {
+      serial_ = serial;
+    }
+
     void MarkAsActive() {
       state_ = kActive;
       ++submit_count_;
@@ -133,6 +141,10 @@ class GLES2_IMPL_EXPORT QueryTracker {
 
     uint32 GetResult() const;
 
+    bool IsInternal() const {
+      return serial_ != 0;
+    }
+
     void Begin(GLES2Implementation* gl);
     void End(GLES2Implementation* gl);
 
@@ -147,6 +159,7 @@ class GLES2_IMPL_EXPORT QueryTracker {
     uint32 submit_count_;
     int32 token_;
     bool flushed_;
+    uint32 serial_; // Only used for internal queries, 0 means not internal.
     uint64 client_begin_time_us_; // Only used for latency query target.
     uint32 result_;
   };
@@ -155,12 +168,15 @@ class GLES2_IMPL_EXPORT QueryTracker {
   ~QueryTracker();
 
   Query* CreateQuery(GLuint id, GLenum target);
+  Query* CreateInternalQuery(GLuint id, GLenum target);
   Query* GetQuery(GLuint id);
   void RemoveQuery(GLuint id);
   void Shrink();
   void FreeCompletedQueries();
 
  private:
+  uint32 NextSerial();
+
   typedef base::hash_map<GLuint, Query*> QueryMap;
   typedef std::list<Query*> QueryList;
 
@@ -168,6 +184,8 @@ class GLES2_IMPL_EXPORT QueryTracker {
   QueryList removed_queries_;
   QuerySyncManager query_sync_manager_;
 
+  uint32 next_serial_;
+
   DISALLOW_COPY_AND_ASSIGN(QueryTracker);
 };