Use relative path to reference the libraries in the NDK.

build/common.gypi

 # Copyright (c) 2012 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.
 
 # IMPORTANT:
 # Please don't directly include this file if you are building via gyp_chromium,
 # since gyp_chromium is automatically forcing its inclusion.
 {
   # Variables expected to be overriden on the GYP command line (-D) or by
   # ~/.gyp/include.gypi.
@@ skipping 1653 matching lines @@
             'ios_breakpad%': 1,
           }, { # else: branding!="Chrome" or buildtype!="Official"
             'ios_breakpad%': 0,
           }],
         ],
       }],  # OS=="ios"
       ['OS=="android"', {
         # Location of Android NDK.
         'variables': {
           'variables': {
-            # Unfortunately we have to use absolute paths to the SDK/NDK because
-            # they're passed to ant which uses a different relative path from
-            # gyp.
-            'android_ndk_root%': '<!(cd <(DEPTH) && pwd -P)/third_party/android_tools/ndk/',
+            # Standard libraries can use the relative path to the NDK.
+            'android_ndk_root%': '../../third_party/android_tools/ndk/',
+            # Unfortunately, it is required to use the absolute path to the SDK
+            # because it us passed to ant which uses a different relative path
+            # from GYP.
             'android_sdk_root%': '<!(cd <(DEPTH) && pwd -P)/third_party/android_tools/sdk/',
+            # Similarly, gdbserver and the Android toolchain need to use the
+            # absolute path to the NDK because they are used at different levels
+            # in the GYP files.
+            'android_ndk_absolute_root%': '<!(cd <(DEPTH) && pwd -P)/third_party/android_tools/ndk/',
             'android_host_arch%': '<!(uname -m)',
             # Android API-level of the SDK used for compilation.
             'android_sdk_version%': '21',
             'android_sdk_build_tools_version%': '21.0.1',
             'host_os%': "<!(uname -s | sed -e 's/Linux/linux/;s/Darwin/mac/')",
           },
           # Copy conditionally-set variables out one scope.
           'android_ndk_root%': '<(android_ndk_root)',
+          'android_ndk_absolute_root%': '<(android_ndk_absolute_root)',
           'android_sdk_root%': '<(android_sdk_root)',
           'android_sdk_version%': '<(android_sdk_version)',
           'android_stlport_root': '<(android_ndk_root)/sources/cxx-stl/stlport',
           'host_os%': '<(host_os)',
 
           'android_sdk%': '<(android_sdk_root)/platforms/android-<(android_sdk_version)',
           # Android SDK build tools (e.g. dx, aapt, aidl)
           'android_sdk_tools%': '<(android_sdk_root)/build-tools/<(android_sdk_build_tools_version)',
 
           # Android API level 14 is ICS (Android 4.0) which is the minimum
           # platform requirement for Chrome on Android, we use it for native
           # code compilation.
           'conditions': [
             ['target_arch == "ia32"', {
               'android_app_abi%': 'x86',
-              'android_gdbserver%': '<(android_ndk_root)/prebuilt/android-x86/gdbserver/gdbserver',
+              'android_gdbserver%': '<(android_ndk_absolute_root)/prebuilt/android-x86/gdbserver/gdbserver',
               'android_ndk_sysroot%': '<(android_ndk_root)/platforms/android-14/arch-x86',
               'android_ndk_lib_dir%': 'usr/lib',
-              'android_toolchain%': '<(android_ndk_root)/toolchains/x86-4.9/prebuilt/<(host_os)-<(android_host_arch)/bin',
+              'android_toolchain%': '<(android_ndk_absolute_root)/toolchains/x86-4.9/prebuilt/<(host_os)-<(android_host_arch)/bin',
             }],
             ['target_arch == "x64"', {
               'android_app_abi%': 'x86_64',
-              'android_gdbserver%': '<(android_ndk_root)/prebuilt/android-x86_64/gdbserver/gdbserver',
+              'android_gdbserver%': '<(android_ndk_absolute_root)/prebuilt/android-x86_64/gdbserver/gdbserver',
               'android_ndk_sysroot%': '<(android_ndk_root)/platforms/android-21/arch-x86_64',
               'android_ndk_lib_dir%': 'usr/lib64',
-              'android_toolchain%': '<(android_ndk_root)/toolchains/x86_64-4.9/prebuilt/<(host_os)-<(android_host_arch)/bin',
+              'android_toolchain%': '<(android_ndk_absolute_root)/toolchains/x86_64-4.9/prebuilt/<(host_os)-<(android_host_arch)/bin',
             }],
             ['target_arch=="arm"', {
               'conditions': [
                 ['arm_version<7', {
                   'android_app_abi%': 'armeabi',
                 }, {
                   'android_app_abi%': 'armeabi-v7a',
                 }],
               ],
-              'android_gdbserver%': '<(android_ndk_root)/prebuilt/android-arm/gdbserver/gdbserver',
+              'android_gdbserver%': '<(android_ndk_absolute_root)/prebuilt/android-arm/gdbserver/gdbserver',
               'android_ndk_sysroot%': '<(android_ndk_root)/platforms/android-14/arch-arm',
               'android_ndk_lib_dir%': 'usr/lib',
-              'android_toolchain%': '<(android_ndk_root)/toolchains/arm-linux-androideabi-4.9/prebuilt/<(host_os)-<(android_host_arch)/bin',
+              'android_toolchain%': '<(android_ndk_absolute_root)/toolchains/arm-linux-androideabi-4.9/prebuilt/<(host_os)-<(android_host_arch)/bin',
             }],
             ['target_arch == "arm64"', {
               'android_app_abi%': 'arm64-v8a',
-              'android_gdbserver%': '<(android_ndk_root)/prebuilt/android-arm64/gdbserver/gdbserver',
+              'android_gdbserver%': '<(android_ndk_absolute_root)/prebuilt/android-arm64/gdbserver/gdbserver',
               'android_ndk_sysroot%': '<(android_ndk_root)/platforms/android-21/arch-arm64',
               'android_ndk_lib_dir%': 'usr/lib',
-              'android_toolchain%': '<(android_ndk_root)/toolchains/aarch64-linux-android-4.9/prebuilt/<(host_os)-<(android_host_arch)/bin',
+              'android_toolchain%': '<(android_ndk_absolute_root)/toolchains/aarch64-linux-android-4.9/prebuilt/<(host_os)-<(android_host_arch)/bin',
             }],
             ['target_arch == "mipsel"', {
               'android_app_abi%': 'mips',
-              'android_gdbserver%': '<(android_ndk_root)/prebuilt/android-mips/gdbserver/gdbserver',
+              'android_gdbserver%': '<(android_ndk_absolute_root)/prebuilt/android-mips/gdbserver/gdbserver',
               'android_ndk_sysroot%': '<(android_ndk_root)/platforms/android-14/arch-mips',
               'android_ndk_lib_dir%': 'usr/lib',
-              'android_toolchain%': '<(android_ndk_root)/toolchains/mipsel-linux-android-4.9/prebuilt/<(host_os)-<(android_host_arch)/bin',
+              'android_toolchain%': '<(android_ndk_absolute_root)/toolchains/mipsel-linux-android-4.9/prebuilt/<(host_os)-<(android_host_arch)/bin',
             }],
             ['target_arch == "mips64el"', {
               'android_app_abi%': 'mips64',
-              'android_gdbserver%': '<(android_ndk_root)/prebuilt/android-mips64/gdbserver/gdbserver',
+              'android_gdbserver%': '<(android_ndk_absolute_root)/prebuilt/android-mips64/gdbserver/gdbserver',
               'android_ndk_sysroot%': '<(android_ndk_root)/platforms/android-21/arch-mips64',
               'android_ndk_lib_dir%': 'usr/lib64',
-              'android_toolchain%': '<(android_ndk_root)/toolchains/mips64el-linux-android-4.9/prebuilt/<(host_os)-<(android_host_arch)/bin',
-              'gcc_version%': 49,

[Nico, 2015/03/03 16:46:27]

Is this no longer needed?

[Fabrice (no longer in Chrome), 2015/03/03 16:54:21]

This is from a time when we were using GCC 4.8 for Android and the mips64
toolchain needed  GCC 4.9. We're now using GCC 4.9 everywhere on Android.

+              'android_toolchain%': '<(android_ndk_absolute_root)/toolchains/mips64el-linux-android-4.9/prebuilt/<(host_os)-<(android_host_arch)/bin',
             }],
           ],
         },
         # Copy conditionally-set variables out one scope.
         'android_app_abi%': '<(android_app_abi)',
         'android_gdbserver%': '<(android_gdbserver)',
         'android_ndk_root%': '<(android_ndk_root)',
         'android_ndk_sysroot%': '<(android_ndk_sysroot)',
         'android_sdk_root%': '<(android_sdk_root)',
         'android_sdk_version%': '<(android_sdk_version)',
@@ skipping 4217 matching lines @@
     # settings in target dicts.  SYMROOT is a special case, because many other
     # Xcode variables depend on it, including variables such as
     # PROJECT_DERIVED_FILE_DIR.  When a source group corresponding to something
     # like PROJECT_DERIVED_FILE_DIR is added to a project, in order for the
     # files to appear (when present) in the UI as actual files and not red
     # red "missing file" proxies, the correct path to PROJECT_DERIVED_FILE_DIR,
     # and therefore SYMROOT, needs to be set at the project level.
     'SYMROOT': '<(DEPTH)/xcodebuild',
   },
 }