allow xgetbv to be disabled for drmemory testing

R=harryjin@google.com
BUG=none

Review URL: https://webrtc-codereview.appspot.com/56649004.

README.chromium

 Name: libyuv
 URL: http://code.google.com/p/libyuv/
-Version: 1459
+Version: 1460
 License: BSD
 License File: LICENSE
 

include/libyuv/version.h

@@ -11,6 +11,6 @@
 #ifndef INCLUDE_LIBYUV_VERSION_H_  // NOLINT
 #define INCLUDE_LIBYUV_VERSION_H_
 
-#define LIBYUV_VERSION 1459
+#define LIBYUV_VERSION 1460
 
 #endif  // INCLUDE_LIBYUV_VERSION_H_  NOLINT

source/cpu_id.cc

@@ -216,8 +216,10 @@ int InitCpuFlags(void) {
               kCpuHasX86;
 
 #ifdef HAS_XGETBV
+  // Avoid call to xgetbv if AVX disabled for drmemory.
+  // TODO(fbarchard): check xsave before calling xgetbv.
   if ((cpu_info1[2] & 0x18000000) == 0x18000000 &&  // AVX and OSSave
-      TestOsSaveYmm()) {  // Saves YMM.
+      !TestEnv("LIBYUV_DISABLE_AVX") && TestOsSaveYmm()) {  // Saves YMM.
     cpu_info_ |= ((cpu_info7[1] & 0x00000020) ? kCpuHasAVX2 : 0) |
                  kCpuHasAVX;
   }
@@ -238,9 +240,6 @@ int InitCpuFlags(void) {
   if (TestEnv("LIBYUV_DISABLE_SSE42")) {
     cpu_info_ &= ~kCpuHasSSE42;
   }
-  if (TestEnv("LIBYUV_DISABLE_AVX")) {
-    cpu_info_ &= ~kCpuHasAVX;
-  }
   if (TestEnv("LIBYUV_DISABLE_AVX2")) {
     cpu_info_ &= ~kCpuHasAVX2;
   }