Add headers to gn/gni files for all of sky/engine

sky/engine/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("config.gni")
 if (is_clang) {
   import("//build/config/clang/clang.gni")
 }
 if (is_posix) {
   import("//build/config/gcc/gcc_version.gni")
@@ skipping 20 matching lines @@
 
 config("config") {
   include_dirs = [
     ".",
     "$root_gen_dir/sky",
   ]
 
   cflags = []
   defines = []
 
-  if (is_win) {
-    cflags += [
-      "/wd4065",  # Switch statement contains 'default' but no 'case' labels.
-                  # In generated parser code.
-      "/wd4305",  # Truncation from 'type1' to 'type2'.
-      "/wd4324",  # Struct padded due to declspec(align).
-      "/wd4702",  # Unreachable code, happens in bison-generated code.
-      "/wd4714",  # Function marked forceinline not inlined.
-      "/wd4800",  # Value forced to bool.
-      "/wd4996",  # Deprecated function call.
-    ]
-  }
+  # TODO(GYP) this should be based on gcc_version >= 46 but GN doesn't have a
+  # concept of GCC version yet.
 
-  if (is_win) {
-    if (component_mode == "shared_library") {
-      defines += [ "USING_V8_SHARED" ]
-    }
-  } else {  # ! Windows
-    # TODO(GYP) this should be based on gcc_version >= 46 but GN doesn't have a
-    # concept of GCC version yet.
-
-    # Disable warnings about c++0x compatibility, as some names (such as
-    # nullptr) conflict with upcoming c++0x types.
-    cflags_cc = [ "-Wno-c++0x-compat" ]
-  }
+  # Disable warnings about c++0x compatibility, as some names (such as
+  # nullptr) conflict with upcoming c++0x types.
+  cflags_cc = [ "-Wno-c++0x-compat" ]
 
   if (is_linux && cpu_arch == "arm") {
     # Due to a bug in gcc arm, we get warnings about uninitialized
     # timesNewRoman.unstatic.3258 and colorTransparent.unstatic.4879.
     cflags += [ "-Wno-uninitialized" ]
   }
 
   if (is_posix && gcc_version >= 49) {
     cflags += [ "-Wno-unused-but-set-variable" ]
   }
 
   if (is_clang) {
     if (sky_gc_plugin && clang_use_chrome_plugins) {
       # TODO(GYP)
       #'cflags': ['<!@(../../tools/clang/scripts/blink_gc_plugin_flags.sh enable-oilpan=<(sky_enable_oilpan) dump-graph=<(sky_gc_plugin_dump_graph))'],
     }
   }
 }
 
 # The follow configs apply to all targets except for unit tests, which rely on
 # static initializers.
 config("non_test_config") {
   cflags = []
 
   if (is_clang) {
     cflags += [ "-Wglobal-constructors" ]
   }
 }