Moving ICU dependent function ReadUTFChar into the icu.cc file....

src/url_canon_icu.cc

Index: src/url_canon_icu.cc
===================================================================
--- src/url_canon_icu.cc	(revision 104)
+++ src/url_canon_icu.cc	(working copy)
@@ -161,4 +161,47 @@
   }
 }
 
+bool ReadUTFChar(const char* str, int* begin, int length,
+                 unsigned* code_point_out) {
+  int code_point;  // Avoids warning when U8_NEXT writes -1 to it.
+  U8_NEXT(str, *begin, length, code_point);
+  *code_point_out = static_cast<unsigned>(code_point);
+
+  // The ICU macro above moves to the next char, we want to point to the last
+  // char consumed.
+  (*begin)--;
+
+  // Validate the decoded value.
+  if (U_IS_UNICODE_CHAR(code_point))
+    return true;
+  *code_point_out = kUnicodeReplacementCharacter;
+  return false;
+}
+
+bool ReadUTFChar(const char16* str, int* begin, int length,
+                 unsigned* code_point) {
+  if (U16_IS_SURROGATE(str[*begin])) {
+    if (!U16_IS_SURROGATE_LEAD(str[*begin]) || *begin + 1 >= length ||
+        !U16_IS_TRAIL(str[*begin + 1])) {
+      // Invalid surrogate pair.
+      *code_point = kUnicodeReplacementCharacter;
+      return false;
+    } else {
+      // Valid surrogate pair.
+      *code_point = U16_GET_SUPPLEMENTARY(str[*begin], str[*begin + 1]);
+      (*begin)++;
+    }
+  } else {
+    // Not a surrogate, just one 16-bit word.
+    *code_point = str[*begin];
+  }
+
+  if (U_IS_UNICODE_CHAR(*code_point))
+    return true;
+
+  // Invalid code point.
+  *code_point = kUnicodeReplacementCharacter;
+  return false;
+}
+
 }  // namespace url_canon