detect neon for ndk but not sdk

BUG=none
TEST=none
Review URL: https://webrtc-codereview.appspot.com/366005

git-svn-id: http://libyuv.googlecode.com/svn/trunk@152 16f28f9a-4ce2-e073-06de-1de4eb20be90

README.chromium

 Name: libyuv
 URL: http://code.google.com/p/libyuv/
-Version: 151
+Version: 152
 License: BSD
 License File: LICENSE
 

include/libyuv/version.h

@@ -16,7 +16,7 @@ namespace libyuv {
 extern "C" {
 #endif
 
-#define LIBYUV_VERSION 151
+#define LIBYUV_VERSION 152
 
 #ifdef __cplusplus
 }  // extern "C"

source/cpu_id.cc

@@ -14,7 +14,7 @@
 #ifdef _MSC_VER
 #include <intrin.h>  // For __cpuid()
 #endif
-#ifdef __ANDROID__
+#if defined(__ANDROID__) && defined(NDK_ROOT)
 #include <cpu-features.h>  // For android_getCpuFeatures()
 #endif
 
@@ -65,7 +65,7 @@ int InitCpuFlags() {
   if (getenv("LIBYUV_DISABLE_SSSE3")) {
     cpu_info_ &= ~kCpuHasSSSE3;
   }
-#elif defined(__ANDROID__) && defined(__ARM_NEON__)
+#elif defined(__ANDROID__) && defined(__ARM_NEON__) && defined(NDK_ROOT)
   uint64_t features = android_getCpuFeatures();
   cpu_info_ = ((features & ANDROID_CPU_ARM_FEATURE_NEON) ? kCpuHasNEON : 0) |
               kCpuInitialized;