HasOnlyAsciiChars can return incorrect results. Fixup usages and rename.

src/log.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 317 matching lines @@
 class Logger::NameBuffer {
  public:
   NameBuffer() { Reset(); }
 
   void Reset() {
     utf8_pos_ = 0;
   }
 
   void AppendString(String* str) {
     if (str == NULL) return;
-    if (str->HasOnlyAsciiChars()) {
-      int utf8_length = Min(str->length(), kUtf8BufferSize - utf8_pos_);
-      String::WriteToFlat(str,
-                          reinterpret_cast<uint8_t*>(utf8_buffer_ + utf8_pos_),
-                          0,
-                          utf8_length);
-      utf8_pos_ += utf8_length;
-      return;
-    }
     int uc16_length = Min(str->length(), kUtf16BufferSize);
     String::WriteToFlat(str, utf16_buffer, 0, uc16_length);
     int previous = unibrow::Utf16::kNoPreviousCharacter;
     for (int i = 0; i < uc16_length && utf8_pos_ < kUtf8BufferSize; ++i) {
       uc16 c = utf16_buffer[i];
       if (c <= unibrow::Utf8::kMaxOneByteChar) {
         utf8_buffer_[utf8_pos_++] = static_cast<char>(c);
       } else {
         int char_length = unibrow::Utf8::Length(c, previous);
         if (utf8_pos_ + char_length > kUtf8BufferSize) break;
@@ skipping 1536 matching lines @@
     profiler_ = NULL;
   }
 
   delete ticker_;
   ticker_ = NULL;
 
   return log_->Close();
 }
 
 } }  // namespace v8::internal