Perform glReadPixels with PBOs in the gpu, if PBOs are available.

gpu/command_buffer/client/query_tracker.cc

 // 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.
 
 #include "gpu/command_buffer/client/query_tracker.h"
 
 #include <GLES2/gl2.h>
 #include <GLES2/gl2ext.h>
 #include <GLES2/gl2extchromium.h>
 
@@ skipping 95 matching lines @@
   switch (target()) {
     case GL_GET_ERROR_QUERY_CHROMIUM:
       // To nothing on begin for error queries.
       break;
     case GL_LATENCY_QUERY_CHROMIUM:
       client_begin_time_us_ = MicrosecondsSinceOriginOfTime();
       // tell service about id, shared memory and count
       gl->helper()->BeginQueryEXT(target(), id(), shm_id(), shm_offset());
       break;
     case GL_ASYNC_PIXEL_TRANSFERS_COMPLETED_CHROMIUM:
-      // tell service about id, shared memory and count
-      gl->helper()->BeginQueryEXT(target(), id(), shm_id(), shm_offset());
-      break;
+    case GL_ASYNC_READ_PIXELS_COMPLETED_CHROMIUM:
     default:
       // tell service about id, shared memory and count
       gl->helper()->BeginQueryEXT(target(), id(), shm_id(), shm_offset());
       break;
   }
 }
 
 void QueryTracker::Query::End(GLES2Implementation* gl) {
   switch (target()) {
     case GL_GET_ERROR_QUERY_CHROMIUM: {
@@ skipping 29 matching lines @@
         case GL_COMMANDS_ISSUED_CHROMIUM:
           result_ = std::min(info_.sync->result,
                              static_cast<uint64>(0xFFFFFFFFL));
           break;
         case GL_LATENCY_QUERY_CHROMIUM:
           GPU_DCHECK(info_.sync->result >= client_begin_time_us_);
           result_ = std::min(info_.sync->result - client_begin_time_us_,
                              static_cast<uint64>(0xFFFFFFFFL));
           break;
         case GL_ASYNC_PIXEL_TRANSFERS_COMPLETED_CHROMIUM:
-          result_ = info_.sync->result;
-          break;
+        case GL_ASYNC_READ_PIXELS_COMPLETED_CHROMIUM:
         default:
           result_ = info_.sync->result;
           break;
       }
       state_ = kComplete;
     } else {
       if (!flushed_) {
         // TODO(gman): We could reduce the number of flushes by having a
         // flush count, recording that count at the time we insert the
         // EndQuery command and then only flushing here if we've have not
@@ skipping 52 matching lines @@
     delete query;
   }
 }
 
 void QueryTracker::Shrink() {
   query_sync_manager_.Shrink();
 }
 
 }  // namespace gles2
 }  // namespace gpu