Fixing some warning due to different signess of char

BUG=None
TEST=None

Review URL: http://codereview.chromium.org/8354008

Review URL: http://codereview.chromium.org/8354008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@110968 0039d316-1c4b-4281-b951-d872f2087c98

base/string_split.cc

@@ -45,7 +45,10 @@ void SplitString(const string16& str,
 void SplitString(const std::string& str,
                  char c,
                  std::vector<std::string>* r) {
-  DCHECK(c >= 0 && c < 0x7F);
+#if CHAR_MIN < 0
+  DCHECK(c >= 0);
+#endif
+  DCHECK(c < 0x7F);
   SplitStringT(str, c, true, r);
 }
 
@@ -156,7 +159,10 @@ void SplitStringDontTrim(const std::string& str,
                          char c,
                          std::vector<std::string>* r) {
   DCHECK(IsStringUTF8(str));
-  DCHECK(c >= 0 && c < 0x7F);
+#if CHAR_MIN < 0
+  DCHECK(c >= 0);
+#endif
+  DCHECK(c < 0x7F);
   SplitStringT(str, c, false, r);
 }
 

net/base/dns_util.cc

@@ -60,7 +60,11 @@ std::string DNSDomainToString(const std::string& domain) {
   std::string ret;
 
   for (unsigned i = 0; i < domain.size() && domain[i]; i += domain[i] + 1) {
-    if (domain[i] < 0 || domain[i] > 63)
+#if CHAR_MIN < 0
+    if (domain[i] < 0)
+      return "";
+#endif
+    if (domain[i] > 63)
       return "";
 
     if (i)