Increase error tolerance to 4 for arm on J420 convert

BUG=libyuv:479
R=harryjin@google.com

Review URL: https://webrtc-codereview.appspot.com/53789004.

README.chromium

 Name: libyuv
 URL: http://code.google.com/p/libyuv/
-Version: 1460
+Version: 1461
 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 1460
+#define LIBYUV_VERSION 1461
 
 #endif  // INCLUDE_LIBYUV_VERSION_H_  NOLINT

unit_test/color_test.cc

@@ -27,11 +27,13 @@ namespace libyuv {
 #define ERROR_G 1
 #define ERROR_B 3
 #define ERROR_FULL 6
+#define ERROR_J420 4
 #else
 #define ERROR_R 1
 #define ERROR_G 1
 #define ERROR_B 3
 #define ERROR_FULL 5
+#define ERROR_J420 3
 #endif
 
 #define TESTCS(TESTNAME, YUVTOARGB, ARGBTOYUV, HS1, HS, HN, DIFF)              \
@@ -131,7 +133,7 @@ TEST_F(libyuvTest, TESTNAME) {                                                 \
 
 TESTCS(TestI420, I420ToARGB, ARGBToI420, 1, 2, benchmark_width_, ERROR_FULL)
 TESTCS(TestI422, I422ToARGB, ARGBToI422, 0, 1, 0, ERROR_FULL)
-TESTCS(TestJ420, J420ToARGB, ARGBToJ420, 1, 2, benchmark_width_, 3)
+TESTCS(TestJ420, J420ToARGB, ARGBToJ420, 1, 2, benchmark_width_, ERROR_J420)
 TESTCS(TestJ422, J422ToARGB, ARGBToJ422, 0, 1, 0, 3)
 
 static void YUVToRGB(int y, int u, int v, int* r, int* g, int* b) {
@@ -435,7 +437,7 @@ TEST_F(libyuvTest, TestGreyYUV) {
   }
 }
 
-void PrintHistogram(int rh[256], int gh[256], int bh[256]) {
+static void PrintHistogram(int rh[256], int gh[256], int bh[256]) {
   int i;
   printf("hist");
   for (i = 0; i < 256; ++i) {