Support ARB extensions for indirect drawing

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 500 matching lines @@
                 (ctxInfo.hasExtension("GL_ARB_draw_instanced") &&
                  ctxInfo.hasExtension("GL_ARB_instanced_arrays"));
     } else {
         fSupportsInstancedDraws =
                 version >= GR_GL_VER(3, 0) ||
                 (ctxInfo.hasExtension("GL_EXT_draw_instanced") &&
                  ctxInfo.hasExtension("GL_EXT_instanced_arrays"));
     }
 
     if (kGL_GrGLStandard == standard) {
-        // We don't use ARB_draw_indirect because it does not support a base instance.
-        // We don't use ARB_multi_draw_indirect because it does not support GL_DRAW_INDIRECT_BUFFER.
-        fDrawIndirectSupport =
-            fMultiDrawIndirectSupport = fBaseInstanceSupport = version >= GR_GL_VER(4,3);
+        fDrawIndirectSupport = version >= GR_GL_VER(4,0) ||
+                               ctxInfo.hasExtension("GL_ARB_draw_indirect");
+        fBaseInstanceSupport = version >= GR_GL_VER(4,2);
+        fMultiDrawIndirectSupport = version >= GR_GL_VER(4,3) ||
+                                    (!fBaseInstanceSupport && // The ARB extension has no base inst.
+                                     ctxInfo.hasExtension("GL_ARB_multi_draw_indirect"));
     } else {
         fDrawIndirectSupport = version >= GR_GL_VER(3,1);
         fMultiDrawIndirectSupport = ctxInfo.hasExtension("GL_EXT_multi_draw_indirect");
         fBaseInstanceSupport = ctxInfo.hasExtension("GL_EXT_base_instance");
     }
 
     this->initShaderPrecisionTable(ctxInfo, gli, glslCaps);
 
     if (contextOptions.fUseShaderSwizzling) {
         fTextureSwizzleSupport = false;
@@ skipping 1375 matching lines @@
         for (int j = 0; j < kExternalFormatUsageCnt; ++j) {
             SkASSERT(defaultEntry.fFormats.fExternalFormat[j] !=
                      fConfigTable[i].fFormats.fExternalFormat[j]);
         }
         SkASSERT(defaultEntry.fFormats.fExternalType != fConfigTable[i].fFormats.fExternalType);
     }
 #endif
 }
 
 void GrGLCaps::onApplyOptionsOverrides(const GrContextOptions& options) {}