Add NativePixmapDmabufStub to finalize glCreateImageCHROMIUM on Linux.

ui/gfx/BUILD.gn

 # 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.
 
 import("//build/config/ui.gni")
 import("//testing/test.gni")
 import("//testing/libfuzzer/fuzzer_test.gni")
 
 if (is_android) {
   import("//build/config/android/config.gni")
@@ skipping 472 matching lines @@
     ]
   } else {
     public_deps = [
       ":memory_buffer_sources",
     ]
   }
 }
 
 # Cannot be a static_library in component builds due to exported functions
 source_set("memory_buffer_sources") {
-  visibility = [ ":*" ]  # Depend on through ":memory_buffer".
+  visibility = [
+    ":*",
+    "//gpu/ipc/service:gpu_ipc_service_unittests",
+    "//gpu/ipc/service:ipc_service_sources",

[reveman, 2017/04/12 18:21:36]

why is this needed? seems bad to have references to //gpu/ here in ui/gfx/..

[Julien Isorce, 2017/04/13 12:46:02]

I agree, this is because of
https://codereview.chromium.org/2705213005/patch/40001/50001 otherwise I get:

ERROR at //gpu/ipc/service/BUILD.gn:28:1: Dependency not allowed.
target(link_target_type, "ipc_service_sources") {
^------------------------------------------------
The item //gpu/ipc/service:ipc_service_sources
can not depend on //ui/gfx:memory_buffer_sources
because it is not in //ui/gfx:memory_buffer_sources's visibility list: [
  //ui/gfx:*
]

If I remove the change in gpu/ipc/service/BUILD.gn then gn passes but I get
undefined reference to 'gfx::NativePixmapDmaBufStub::NativePixmapDmaBufStub when
compiling for
obj/gpu/ipc/service/ipc_service_sources/gpu_memory_buffer_factory_native_pixmap.o

+  ]  # Depend on through ":memory_buffer".
 
   # TODO(brettw) refactor this so these sources are in a coherent directory
   # structure rather than random samplings of ui/gfx and ui/gfx/mac.
   sources = [
     "buffer_format_util.cc",
     "buffer_format_util.h",
     "buffer_types.h",
     "client_native_pixmap.h",
     "client_native_pixmap_factory.cc",
     "client_native_pixmap_factory.h",
@@ skipping 23 matching lines @@
     "//base",
     "//ui/gfx/geometry",
   ]
 
   if (is_linux) {
     sources += [
       "linux/client_native_pixmap_dmabuf.cc",
       "linux/client_native_pixmap_dmabuf.h",
       "linux/client_native_pixmap_factory_dmabuf.cc",
       "linux/client_native_pixmap_factory_dmabuf.h",
+      "linux/native_pixmap_dmabuf_stub.cc",
+      "linux/native_pixmap_dmabuf_stub.h",
     ]
 
     deps += [ "//third_party/libdrm" ]
   }
 }
 
 static_library("test_support") {
   testonly = true
   sources = [
     "animation/test_animation_delegate.h",
@@ skipping 215 matching lines @@
 
 fuzzer_test("color_transform_fuzztest") {
   sources = [
     "color_transform_fuzzer.cc",
   ]
   deps = [
     ":gfx",
   ]
   libfuzzer_options = [ "max_len=1024" ]
 }