Add support for all blendmodes if we have GL_KHR_blend_equation_advanced.

gpu/command_buffer/common/gles2_cmd_ids_autogen.h

 // Copyright 2014 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.
 
 // This file is auto-generated from
 // gpu/command_buffer/build_gles2_cmd_buffer.py
 // It's formatted by clang-format using chromium coding style:
 //    clang-format -i -style=chromium filename
 // DO NOT EDIT!
 
@@ skipping 191 matching lines @@
   OP(WaitAsyncTexImage2DCHROMIUM)              /* 443 */ \
   OP(WaitAllAsyncTexImage2DCHROMIUM)           /* 444 */ \
   OP(DiscardFramebufferEXTImmediate)           /* 445 */ \
   OP(LoseContextCHROMIUM)                      /* 446 */ \
   OP(InsertSyncPointCHROMIUM)                  /* 447 */ \
   OP(WaitSyncPointCHROMIUM)                    /* 448 */ \
   OP(DrawBuffersEXTImmediate)                  /* 449 */ \
   OP(DiscardBackbufferCHROMIUM)                /* 450 */ \
   OP(ScheduleOverlayPlaneCHROMIUM)             /* 451 */ \
   OP(MatrixLoadfCHROMIUMImmediate)             /* 452 */ \
-  OP(MatrixLoadIdentityCHROMIUM)               /* 453 */
+  OP(MatrixLoadIdentityCHROMIUM)               /* 453 */ \
+  OP(BlendBarrierKHR)                          /* 454 */
 
 enum CommandId {
   kStartPoint = cmd::kLastCommonId,  // All GLES2 commands start after this.
 #define GLES2_CMD_OP(name) k##name,
   GLES2_COMMAND_LIST(GLES2_CMD_OP)
 #undef GLES2_CMD_OP
       kNumCommands
 };
 
 #endif  // GPU_COMMAND_BUFFER_COMMON_GLES2_CMD_IDS_AUTOGEN_H_