Add missing multiview extension check

The extension flag needs to be checked when multiview functions
are called on the GPU command buffer service side.

BUG=870240

Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel
Change-Id: I372593c510154ab96fc7e2415c534a1fc46286e2
Reviewed-on: https://chromium-review.googlesource.com/1161901
Commit-Queue: Kenneth Russell <kbr@chromium.org>
Reviewed-by: Kenneth Russell <kbr@chromium.org>
Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#581066}

gpu/command_buffer/build_gles2_cmd_buffer.py

@@ -4102,6 +4102,7 @@ _FUNCTION_INFO = {
     'decoder_func': 'DoFramebufferTextureMultiviewLayeredANGLE',
     'unit_test': False,
     'extension': 'ANGLE_multiview',
+    'extension_flag': 'angle_multiview',
     'trace_level': 1,
     'es3': True
   },

gpu/command_buffer/service/gles2_cmd_decoder_autogen.h

@@ -5349,6 +5349,10 @@ error::Error GLES2DecoderImpl::HandleFramebufferTextureMultiviewLayeredANGLE(
       *static_cast<
           const volatile gles2::cmds::FramebufferTextureMultiviewLayeredANGLE*>(
           cmd_data);
+  if (!features().angle_multiview) {
+    return error::kUnknownCommand;
+  }
+
   GLenum target = static_cast<GLenum>(c.target);
   GLenum attachment = static_cast<GLenum>(c.attachment);
   GLuint texture = static_cast<GLuint>(c.texture);

gpu/command_buffer/service/gles2_cmd_decoder_passthrough_handlers_autogen.cc

@@ -4728,6 +4728,10 @@ GLES2DecoderPassthroughImpl::HandleFramebufferTextureMultiviewLayeredANGLE(
       *static_cast<
           const volatile gles2::cmds::FramebufferTextureMultiviewLayeredANGLE*>(
           cmd_data);
+  if (!features().angle_multiview) {
+    return error::kUnknownCommand;
+  }
+
   GLenum target = static_cast<GLenum>(c.target);
   GLenum attachment = static_cast<GLenum>(c.attachment);
   GLuint texture = static_cast<GLuint>(c.texture);