Add fence support for TransferBuffers

src/gpu/gl/GrGLCaps.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "GrGLCaps.h"
 
@@ skipping 532 matching lines @@
 
     if (kGL_GrGLStandard == standard) {
         if ((version >= GR_GL_VER(4, 0) || ctxInfo.hasExtension("GL_ARB_sample_shading")) && 
             ctxInfo.vendor() != kIntel_GrGLVendor) {
             fSampleShadingSupport = true;
         }
     } else if (ctxInfo.hasExtension("GL_OES_sample_shading")) {
         fSampleShadingSupport = true;
     }
 
+    // TODO: support CHROMIUM_sync_point and maybe KHR_fence_sync
+    if (kGL_GrGLStandard == standard) {
+        if (version >= GR_GL_VER(3, 2) || ctxInfo.hasExtension("GL_ARB_sync")) {
+            fFenceSyncSupport = true;
+        }
+    } else if (version >= GR_GL_VER(3, 0)) {
+        fFenceSyncSupport = true;
+    }
+
     // We support manual mip-map generation (via iterative downsampling draw calls). This fixes
     // bugs on some cards/drivers that produce incorrect mip-maps for sRGB textures when using
     // glGenerateMipmap. Our implementation requires mip-level sampling control. Additionally,
     // it can be much slower (especially on mobile GPUs), so we opt-in only when necessary:
     if (fMipMapLevelAndLodControlSupport &&
         (contextOptions.fDoManualMipmapping ||
          (kIntel_GrGLVendor == ctxInfo.vendor()) ||
          (kNVIDIA_GrGLDriver == ctxInfo.driver() && isMAC) ||
          (kATI_GrGLVendor == ctxInfo.vendor()))) {
         fDoManualMipmapping = true;
@@ skipping 1398 matching lines @@
 void GrGLCaps::onApplyOptionsOverrides(const GrContextOptions& options) {
     if (options.fEnableInstancedRendering) {
         fInstancedSupport = gr_instanced::GLInstancedRendering::CheckSupport(*this);
 #ifndef SK_BUILD_FOR_MAC
         // OS X doesn't seem to write correctly to floating point textures when using
         // glDraw*Indirect, regardless of the underlying GPU.
         fAvoidInstancedDrawsToFPTargets = true;
 #endif
     }
 }