Add ppapi, improve Windows GN build.

skia/BUILD.gn

 # Copyright (c) 2013 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/features.gni")
 import("//build/config/ui.gni")
 if (cpu_arch == "arm") {
   import("//build/config/arm.gni")
 }
 
@@ skipping 354 matching lines @@
       "//third_party/skia/src/ports/SkFontConfigInterface_direct.cpp",
       "//third_party/skia/src/fonts/SkFontMgr_fontconfig.cpp",
     ]
   }
   if (!is_posix) {
     sources -= [
       "//third_party/skia/src/utils/SkThreadUtils_pthread.cpp",
     ]
   }
 
+  sources -= [
+    # This file is a stub for systems that use pthreads but aren't covered by
+    # one of the more specific pthread files. We don't support any such
+    # systems.
+    "//third_party/skia/src/utils/SkThreadUtils_pthread_other.cpp",
+  ]
+
   if (!use_cairo) {
     sources -= [
       "ext/bitmap_platform_device_cairo.cc",
       "ext/bitmap_platform_device_cairo.h",
     ]
   }
 
   if (is_clang) {
     # Skia won't compile with some of the more strict clang warnings.
     # e.g. it does:
@@ skipping 12 matching lines @@
     ":skia_opts",
     "//base",
     "//base/third_party/dynamic_annotations",
     "//third_party/zlib",
   ]
 
   if (component_mode == "shared_library") {
     defines = [ "SKIA_IMPLEMENTATION=1" ]
   }
 
+  if (is_win) {
+    configs -= [
+      # Some files define WIN32_LEAN_AND_MEAN and we want to avoid a duplicate
+      # definition warning.
+      "//build/config/win:lean_and_mean",
+    ]
+  }
+
   if (is_linux) {
     configs += [
       "//build/config/linux:fontconfig",
       "//build/config/linux:freetype2",
       "//build/config/linux:pangocairo",
     ]
     deps += [
       "//third_party/icu:icuuc",
     ]
   }
@@ skipping 129 matching lines @@
     ":skia_config",
     "//build/config/compiler:no_chromium_code"
   ]
 
   deps = [
     "//base",
   ]
 
   visibility = ":skia"
 }