Lands http://codereview.chromium.org/99349 for Ryan....

base/string_util_unittest.cc

Index: base/string_util_unittest.cc
===================================================================
--- base/string_util_unittest.cc	(revision 15203)
+++ base/string_util_unittest.cc	(working copy)
@@ -311,7 +311,11 @@
   std::wstring converted;
   EXPECT_TRUE(UTF8ToWide("\00Z\t", 3, &converted));
   ASSERT_EQ(3U, converted.length());
+#if defined(WCHAR_T_IS_UNSIGNED)
+  EXPECT_EQ(0U, converted[0]);
+#else
   EXPECT_EQ(0, converted[0]);
+#endif
   EXPECT_EQ('Z', converted[1]);
   EXPECT_EQ('\t', converted[2]);
 
@@ -1509,8 +1513,13 @@
     EXPECT_EQ(1, dst[0]);
     EXPECT_EQ(2, dst[1]);
     EXPECT_EQ(7U, base::wcslcpy(wdst, L"abcdefg", 0));
+#if defined(WCHAR_T_IS_UNSIGNED)
+    EXPECT_EQ(1U, wdst[0]);
+    EXPECT_EQ(2U, wdst[1]);
+#else
     EXPECT_EQ(1, wdst[0]);
     EXPECT_EQ(2, wdst[1]);
+#endif
   }
 
   // Test the case were we _just_ competely fit including the null.