Separate gfx_ipc into skia-dependent and non-skia-dependent parts

ui/gfx/ipc/skia/gfx_skia_param_traits.h

+// Copyright 2016 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.
+
+#ifndef UI_GFX_IPC_GFX_SKIA_PARAM_TRAITS_H_
+#define UI_GFX_IPC_GFX_SKIA_PARAM_TRAITS_H_
+
+#include <string>
+
+#include "ipc/ipc_param_traits.h"
+#include "ui/gfx/ipc/skia/gfx_skia_ipc_export.h"
+
+class SkBitmap;
+
+namespace base {
+class Pickle;
+class PickleIterator;
+}
+
+namespace IPC {
+
+template <>
+struct GFX_SKIA_IPC_EXPORT ParamTraits<SkBitmap> {
+  using param_type = SkBitmap;
+  static void Write(base::Pickle* m, const param_type& p);
+  static bool Read(const base::Pickle* m,
+                   base::PickleIterator* iter,
+                   param_type* r);
+  static void Log(const param_type& p, std::string* l);
+};
+
+}  // namespace IPC
+
+#endif  // UI_GFX_IPC_GFX_SKIA_PARAM_TRAITS_H_