Update from https://crrev.com/303153

build/config/compiler/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/android/config.gni")
 if (cpu_arch == "arm") {
   import("//build/config/arm.gni")
 }
 if (is_posix) {
   import("//build/config/gcc/gcc_version.gni")
@@ skipping 28 matching lines @@
 # source root and might have conflicting versions of some headers) can remove
 # this and specify their own include paths.
 config("default_include_dirs") {
   include_dirs = [
     "//",
     root_gen_dir,
   ]
 }
 
 # TODO(GYP): is_ubsan, is_ubsan_vptr
-using_sanitizer = is_asan || is_lsan || is_tsan || is_msan
+if (!is_win) {
+  using_sanitizer = is_asan || is_lsan || is_tsan || is_msan
+}
 
 # compiler ---------------------------------------------------------------------
 #
 # Base compiler configuration.
 #
 # See also "runtime_library" below for related stuff and a discusison about
 # where stuff should go. Put warning related stuff in the "warnings" config.
 
 config("compiler") {
   cflags = []
@@ skipping 13 matching lines @@
       "/Gy",  # Enable function-level linking.
       "/GS",  # Enable buffer security checking.
       "/FS",  # Preserve previous PDB behavior.
     ]
     if (is_component_build) {
       cflags += [
         "/EHsc",  # Assume C functions can't throw exceptions and don't catch
                   # structured exceptions (only C++ ones).
       ]
     }
-    if (using_sanitizer) {
-      # Avoid error.
-    }
   } else {
     # Common GCC compiler flags setup.
     # --------------------------------
     cflags += [
       "-fno-strict-aliasing",  # See http://crbug.com/32204
     ]
     cflags_cc += [
       "-fno-threadsafe-statics",
       # Not exporting C++ inline functions can generally be applied anywhere
       # so we do so here. Normal function visibility is controlled by
@@ skipping 383 matching lines @@
     # Think of them like system headers, but don't use '-isystem' because the
     # arm-linux-androideabi-4.4.3 toolchain (circa Gingerbread) will exhibit
     # strange errors. The include ordering here is important; change with
     # caution.
     android_stlport_root = "$android_ndk_root/sources/cxx-stl/stlport"
 
     cflags += [
       "-isystem" + rebase_path("$android_stlport_root/stlport",
                                root_build_dir)
     ]
-    lib_dirs += [ "$android_stlport_root/libs/$android_app_abi" ]
+    if (arm_use_thumb) {
+      lib_dirs += [ "$android_stlport_root/libs/$android_app_abi/thumb" ]
+    } else {
+      lib_dirs += [ "$android_stlport_root/libs/$android_app_abi" ]
+    }
 
     if (component_mode == "shared_library") {
       libs += [ "stlport_shared" ]
     } else {
       libs += [ "stlport_static" ]
     }
 
     if (cpu_arch == "mipsel") {
       libs += [
         # ld linker is used for mips Android, and ld does not accept library
@@ skipping 21 matching lines @@
 
 # chromium_code ---------------------------------------------------------------
 #
 # Toggles between higher and lower warnings for code that is (or isn't)
 # part of Chromium.
 
 config("chromium_code") {
   if (is_win) {
     cflags = [
       "/W4",  # Warning level 4.
-      "/wd4267",  # TODO(jschuh): crbug.com/167187 size_t to int truncations.
     ]
   } else {
     cflags = [
       "-Wall",
-      "-Wextra",
 
       # GCC turns on -Wsign-compare for C++ under -Wall, but clang doesn't,
       # so we specify it explicitly.
       # TODO(fischman): remove this if http://llvm.org/PR10448 obsoletes it.
       # http://code.google.com/p/chromium/issues/detail?id=90453
       "-Wsign-compare",
     ]
 
     # In Chromium code, we define __STDC_foo_MACROS in order to get the
     # C99 macros on Mac and Linux.
     defines = [
       "__STDC_CONSTANT_MACROS",
       "__STDC_FORMAT_MACROS",
     ]
   }
 }
 config("no_chromium_code") {
   cflags = []
   cflags_cc = []
   defines = []
 
   if (is_win) {
     cflags += [
       "/W3",  # Warning level 3.
       "/wd4800",  # Disable warning when forcing value to bool.
-      "/wd4267",  # TODO(jschuh): crbug.com/167187 size_t to int truncations.
     ]
     defines += [
       "_CRT_NONSTDC_NO_WARNINGS",
       "_CRT_NONSTDC_NO_DEPRECATE",
     ]
   }
 
   if (is_linux) {
     # Don't warn about ignoring the return value from e.g. close(). This is
     # off by default in some gccs but on by default in others. BSD systems do
@@ skipping 384 matching lines @@
       cflags += [ "-gsplit-dwarf" ]
     }
   }
 }
 
 config("no_symbols") {
   if (!is_win) {
     cflags = [ "-g0" ]
   }
 }