Move more of webcore_remaining into GN build files.

third_party/WebKit/Source/core/clipboard/BUILD.gn

+# 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.
+
+import("//third_party/WebKit/Source/core/core.gni")
+
+blink_core_sources("clipboard") {
+  sources = [
+    "DataObject.cpp",
+    "DataObject.h",
+    "DataObjectItem.cpp",
+    "DataObjectItem.h",
+    "DataTransfer.cpp",
+    "DataTransfer.h",
+    "DataTransferItem.cpp",
+    "DataTransferItem.h",
+    "DataTransferItemList.cpp",
+    "DataTransferItemList.h",
+    "DraggedIsolatedFileSystem.cpp",
+    "DraggedIsolatedFileSystem.h",
+    "Pasteboard.cpp",
+    "Pasteboard.h",
+  ]
+
+  configs += [
+    # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
+    "//build/config/compiler:no_size_t_to_int_warning",
+  ]
+}