Fix: Adding list of supported codecs for MP4 containers

base/strings/string_util_unittest.cc

Index: base/strings/string_util_unittest.cc
diff --git a/base/strings/string_util_unittest.cc b/base/strings/string_util_unittest.cc
index e447cdc39024cce1eebc3e9932a3d61602a54d3b..d7f0a65909892d18e12e66f30f2aa2dd6095c323 100644
--- a/base/strings/string_util_unittest.cc
+++ b/base/strings/string_util_unittest.cc
@@ -594,6 +594,18 @@ TEST(StringUtilTest, HexDigitToInt) {
   EXPECT_EQ(15, HexDigitToInt('f'));
 }
 
+TEST(StringUtilTest, UpperCaseHexNumber) {
+  EXPECT_TRUE(IsUpperCaseHexNumber("1234567890"));
+  EXPECT_TRUE(IsUpperCaseHexNumber("ABDCEF"));
+  EXPECT_TRUE(IsUpperCaseHexNumber("1A2B3C"));
+
+  EXPECT_FALSE(IsUpperCaseHexNumber(""));
+  EXPECT_FALSE(IsUpperCaseHexNumber("1a2b3c"));
+  EXPECT_FALSE(IsUpperCaseHexNumber("abcdef"));
+  EXPECT_FALSE(IsUpperCaseHexNumber("GHIJKL"));
+  EXPECT_FALSE(IsUpperCaseHexNumber("!@#$^&*|"));
+}
+
 // This checks where we can use the assignment operator for a va_list. We need
 // a way to do this since Visual C doesn't support va_copy, but assignment on
 // va_list is not guaranteed to be a copy. See StringAppendVT which uses this