Android WebView: Fall back to idle uploads if draw functor table not set

gpu/command_buffer/service/async_pixel_transfer_manager_android.cc

 // Copyright 2013 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/service/async_pixel_transfer_manager.h"
 
 #include "base/debug/trace_event.h"
 #include "base/sys_info.h"
 #include "gpu/command_buffer/service/async_pixel_transfer_manager_egl.h"
 #include "gpu/command_buffer/service/async_pixel_transfer_manager_idle.h"
 #include "gpu/command_buffer/service/async_pixel_transfer_manager_stub.h"
 #include "gpu/command_buffer/service/async_pixel_transfer_manager_sync.h"
+#include "gpu/command_buffer/service/mailbox_synchronizer.h"
 #include "ui/gl/gl_context.h"
 #include "ui/gl/gl_implementation.h"
 
 namespace gpu {
 namespace {
 
 bool IsBroadcom() {
   const char* vendor = reinterpret_cast<const char*>(glGetString(GL_VENDOR));
   if (vendor)
     return std::string(vendor).find("Broadcom") != std::string::npos;
@@ skipping 33 matching lines @@
     case gfx::kGLImplementationEGLGLES2:
       DCHECK(context);
       if (context->HasExtension("EGL_KHR_fence_sync") &&
           context->HasExtension("EGL_KHR_image") &&
           context->HasExtension("EGL_KHR_image_base") &&
           context->HasExtension("EGL_KHR_gl_texture_2D_image") &&
           context->HasExtension("GL_OES_EGL_image") &&
           !IsBroadcom() &&
           !IsImagination() &&
           !IsNvidia31() &&
-          !base::SysInfo::IsLowEndDevice()) {
+          !base::SysInfo::IsLowEndDevice() &&
+          !gles2::MailboxSynchronizer::GetInstance()) {

[boliu, 2014/07/24 01:29:07]

What does the rest of this change have to do with MailboxSynchronizer? That's
initialized in aw_browser_main_parts.cc

[no sievers, 2014/07/24 16:59:39]

This async upload impl does not work with mailbox sync because it creates EGL
images for the textures also.
Disabling it here makes it fall back to the idle uploader.

[boliu, 2014/07/24 17:00:59]

I don't see how the functor table not being set leads to MailboxSynchronizer not
being initialized though.

[no sievers, 2014/07/24 19:21:26]

It has nothing to do with the draw functor table.
The draw functor table not being set falls back to async uploads.
MailboxSync enabled disallows AsyncPixelTransferManagerEGL.

[boliu, 2014/07/24 20:50:24]

Oh...that wasn't obvious

         return new AsyncPixelTransferManagerEGL;
       }
       return new AsyncPixelTransferManagerIdle;
     case gfx::kGLImplementationOSMesaGL:
       return new AsyncPixelTransferManagerIdle;
     case gfx::kGLImplementationMockGL:
       return new AsyncPixelTransferManagerStub;
     default:
       NOTREACHED();
       return NULL;
   }
 }
 
 }  // namespace gpu