Move more string_util functions to base namespace.

Rename IsWhitespace to IsUnicodeWhitespace (to contrast it to the already-existing IsAsciiWhitespace).

De-inline HexDigitToInt. This is only used in a few places and I don't think it's necessary to inline.

Remove some redundant base:: qualifications in base.

TBR=sky

Review URL: https://codereview.chromium.org/1200053004

Cr-Commit-Position: refs/heads/master@{#335827}
diff --git a/chrome/browser/internal_auth.cc b/chrome/browser/internal_auth.cc
index 4286011..c3f44c7cd 100644
--- a/chrome/browser/internal_auth.cc
+++ b/chrome/browser/internal_auth.cc
@@ -112,7 +112,7 @@
       var.size() <= kStringLengthLimit &&
       base::IsStringASCII(var) &&
       var.find_first_not_of(kAllowedChars) == std::string::npos &&
-      !IsAsciiDigit(var[0]);
+      !base::IsAsciiDigit(var[0]);
 }
 
 bool IsValueSane(const std::string& value) {
@@ -448,7 +448,7 @@
 void InternalAuthVerification::ChangeKey(const std::string& key) {
   base::AutoLock alk(g_verification_service_lock.Get());
   g_verification_service.Get().ChangeKey(key);
-};
+}
 
 // static
 int InternalAuthVerification::get_verification_window_ticks() {