Add build_config_functions.h to avoid #ifdef

sandbox/linux/tests/unit_tests.cc

Index: sandbox/linux/tests/unit_tests.cc
diff --git a/sandbox/linux/tests/unit_tests.cc b/sandbox/linux/tests/unit_tests.cc
index ad30d840f43acf7c573442892692612b0cd0aabf..01844d28641479a97e1606c58801b1534b659f09 100644
--- a/sandbox/linux/tests/unit_tests.cc
+++ b/sandbox/linux/tests/unit_tests.cc
@@ -41,22 +41,6 @@ int CountThreads() {
 
 namespace sandbox {
 
-bool IsAndroid() {
-#if defined(OS_ANDROID)
-  return true;
-#else
-  return false;
-#endif
-}
-
-bool IsArchitectureArm() {
-#if defined(ARCH_CPU_ARM_FAMILY)
-  return true;
-#else
-  return false;
-#endif
-}
-
 // TODO(jln): figure out why base/.../dynamic_annotations.h's
 // RunningOnValgrind() cannot link.
 bool IsRunningOnValgrind() { return RUNNING_ON_VALGRIND; }