Fixes Android build by using C++ math header instead of C one.

tools/gyp/configurations_android.gypi

 # Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 # Definitions for building standalone Dart binaries to run on Android.
 # This is mostly excerpted from:
 # http://src.chromium.org/viewvc/chrome/trunk/src/build/common.gypi
 
 {
   'variables': {
     'android_ndk_root': '<(PRODUCT_DIR)/../../third_party/android_tools/ndk',
   },  # variables
   'target_defaults': {
     'configurations': {
       # It is very important to get the order of the linker arguments correct.
       # Therefore, we put them all in the architecture specific configurations,
       # even though there are many flags in common, to avoid splitting them
       # between two configurations and possibly accidentally mixing up the
       # order.
       'Dart_Android_Base': {
         'abstract': 1,
         'cflags': [ '-Wno-abi', '-Wall', '-W', '-Wno-unused-parameter',
                     '-Wnon-virtual-dtor', '-fno-rtti', '-fno-exceptions',],
         'target_conditions': [
           ['_toolset=="target"', {
             'defines': [
               'ANDROID',
               'USE_STLPORT=1',
+              '__GNU_SOURCE=1',
               '_STLP_USE_PTR_SPECIALIZATIONS=1',
-              '_STLP_NO_CSTD_FUNCTION_IMPORTS=1',
               'HAVE_OFF64_T',
               'HAVE_SYS_UIO_H',
             ],
             'cflags!': [
               '-pthread',  # Not supported by Android toolchain.
             ],
             'cflags': [
               '-U__linux__',  # Don't allow toolchain to claim -D__linux__
               '-ffunction-sections',
               '-funwind-tables',
@@ skipping 38 matching lines @@
           'android_ndk_include': '<(android_sysroot)/usr/include',
           'android_ndk_lib': '<(android_sysroot)/usr/lib',
         },
         'target_conditions': [
           ['_toolset=="target"', {
             # The x86 toolchain currently has problems with stack-protector.
             'cflags!': [
               '-fstack-protector',
             ],
             'cflags': [
+              '--sysroot=<(android_sysroot)',
               '-I<(android_ndk_include)',
               '-I<(android_ndk_root)/sources/cxx-stl/stlport/stlport',
               '-fno-stack-protector',
             ],
             'target_conditions': [
               ['_type=="executable"', {
                 'ldflags!': ['-Wl,--exclude-libs=ALL,-shared',],
               }],
               ['_type=="shared_library"', {
                 'ldflags': ['-Wl,-shared,-Bsymbolic',],
@@ skipping 35 matching lines @@
       'Dart_Android_arm_Base': {
         'abstract': 1,
         'variables': {
           'android_sysroot': '<(android_ndk_root)/platforms/android-14/arch-arm',
           'android_ndk_include': '<(android_sysroot)/usr/include',
           'android_ndk_lib': '<(android_sysroot)/usr/lib',
         },
         'target_conditions': [
           ['_toolset=="target"', {
             'cflags': [
+              '--sysroot=<(android_sysroot)',
               '-I<(android_ndk_include)',
               '-I<(android_ndk_root)/sources/cxx-stl/stlport/stlport',
               '-march=armv7-a',
               '-mtune=cortex-a8',
               '-mfpu=vfp3',
               '-mfloat-abi=softfp',
             ],
             'target_conditions': [
               ['_type=="executable"', {
                 'ldflags!': ['-Wl,--exclude-libs=ALL,-shared',],
@@ skipping 27 matching lines @@
             ],
           }],
           ['_toolset=="host"', {
             'ldflags': [ '-m32', '-pthread' ],
           }],
         ],
       },
     },  # configurations
   },  # target_defaults
 }