Enable size_t to int truncation warnings in PPAPI

ppapi/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.
 
 gypi_values = exec_script("//build/gypi_to_gn.py",
                           [ rebase_path("ppapi_sources.gypi") ],
                           "scope",
                           [ "ppapi_sources.gypi" ])
 
 # TODO(GYP) support chrome_multiple_dll
@@ skipping 11 matching lines @@
 # Some targets need to depend on the PPAPI version only. This target exists so
 # they can include this header without header check warnings.
 source_set("ppapi_macros") {
   sources = [
     "c/pp_macros.h",
   ]
 }
 
 source_set("ppapi_cpp_objects") {
   sources = gypi_values.cpp_source_files
-
-  if (is_win) {
-    cflags = [ "/we4244" ]  # Implicit conversion, possible loss of data.
-  } else {
-    cflags = [
-      "-Wextra",
-      "-pedantic",
-    ]
-  }
 }
 
 source_set("ppapi_cpp") {
   sources = [
     "cpp/module_embedder.h",
     "cpp/ppp_entrypoints.cc",
   ]
 
-  if (is_posix) {
-    cflags = [
-      "-Wextra",
-      "-pedantic",
-    ]
-  }
-
   deps = [
     ":ppapi_c",
     ":ppapi_cpp_objects",
   ]
 }
 
 source_set("ppapi_internal_module") {
   sources = [
     "cpp/private/internal_module.cc",
     "cpp/private/internal_module.h",
@@ skipping 360 matching lines @@
     "//media:shared_memory_support",
     "//skia",
     "//third_party/icu:icuuc",
     "//ui/events:events_base",
     "//ui/surface",
     "//url",
   ]
 
   if (is_mac) {
     libs = [ "QuartzCore.framework" ]
-  } else if (is_win) {
-    cflags = [ "/wd4267" ]  # size_t to int truncation.
   }
 }
 
 source_set("ppapi_ipc") {
   sources = [
     "proxy/nacl_message_scanner.cc",
     "proxy/nacl_message_scanner.h",
     "proxy/ppapi_messages.cc",
     "proxy/ppapi_messages.h",
     "proxy/ppapi_param_traits.cc",
@@ skipping 295 matching lines @@
     "//gpu/command_buffer/client:gles2_implementation",
     "//gpu/ipc",
     "//media:shared_memory_support",
     "//ipc",
     "//skia",
     "//third_party/icu",
     "//ui/events:events_base",
     "//ui/surface",
     blink_target,
   ]
-
-  if (is_win) {
-    cflags = [ "/wd4267" ]  # size_t to int truncation.
-  }
 }
 
 component("ppapi_host") {
   sources = [
     "host/dispatch_host_message.h",
     "host/error_conversion.cc",
     "host/error_conversion.h",
     "host/host_factory.h",
     "host/host_message_context.cc",
     "host/host_message_context.h",
@@ skipping 45 matching lines @@
     ":ppapi_proxy",
     ":ppapi_shared",
     "//base/test:test_support",
     "//ipc",
     "//ipc:test_support",
     "//testing/gmock",
     "//testing/gtest",
   ]
 }
 # TODO(GYP) other targets from ppapi_tests.gyp