Update uses of UTF conversions in content/ to use the base:: namespace.

content/common/sandbox_mac_diraccess_unittest.mm

Index: content/common/sandbox_mac_diraccess_unittest.mm
diff --git a/content/common/sandbox_mac_diraccess_unittest.mm b/content/common/sandbox_mac_diraccess_unittest.mm
index 6d3ddadb367851b5f40371f9ee87c570d1420cee..45c730c673513f08c15d1135231d7a5fe1474596 100644
--- a/content/common/sandbox_mac_diraccess_unittest.mm
+++ b/content/common/sandbox_mac_diraccess_unittest.mm
@@ -99,13 +99,14 @@ TEST_F(MacDirAccessSandboxTest, RegexEscape) {
     EXPECT_TRUE(Sandbox::QuoteStringForRegex("}", &out));   // } == 0x7D == 125
     EXPECT_FALSE(Sandbox::QuoteStringForRegex("~", &out));  // ~ == 0x7E == 126
     EXPECT_FALSE(
-        Sandbox::QuoteStringForRegex(WideToUTF8(L"^\u2135.\u2136$"), &out));
+        Sandbox::QuoteStringForRegex(base::WideToUTF8(L"^\u2135.\u2136$"),
+                                     &out));
   }
 
   {
     for (size_t i = 0; i < ARRAYSIZE_UNSAFE(regex_cases); ++i) {
       std::string out;
-      std::string in = WideToUTF8(regex_cases[i].to_escape);
+      std::string in = base::WideToUTF8(regex_cases[i].to_escape);
       EXPECT_TRUE(Sandbox::QuoteStringForRegex(in, &out));
       std::string expected("^");
       expected.append(regex_cases[i].escaped);