A fix for Issue 4400 (or maybe 4222)....

chrome/common/gfx/chrome_font_win.cc

 // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/common/gfx/chrome_font.h"
 
 #include <windows.h>
 #include <math.h>
 
 #include <algorithm>
@@ skipping 25 matching lines @@
 
 int ChromeFont::baseline() const {
   return font_ref_->baseline();
 }
 
 int ChromeFont::ave_char_width() const {
   return font_ref_->ave_char_width();
 }
 
 int ChromeFont::GetExpectedTextWidth(int length) const {
-  return length * font_ref_->dlu_base_x();
+  return length * std::min(font_ref_->dlu_base_x(), ave_char_width());
 }
 
 int ChromeFont::style() const {
   return font_ref_->style();
 }
 
 NativeFont ChromeFont::nativeFont() const {
   return hfont();
 }
 
@@ skipping 11 matching lines @@
   long lf_height = -MulDiv(font_size, GetDeviceCaps(hdc, LOGPIXELSY), 72);
   ReleaseDC(NULL, hdc);
   HFONT hf = ::CreateFont(lf_height, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
                     font_name.c_str());
   return ChromeFont::CreateFont(hf);
 }
 
 // static
 ChromeFont::HFontRef* ChromeFont::GetBaseFontRef() {
   if (base_font_ref_ == NULL) {
-                NONCLIENTMETRICS metrics;
+    NONCLIENTMETRICS metrics;
     win_util::GetNonClientMetrics(&metrics);
 
     // See comment in ChromeFont::DeriveFont() about font size.
     DCHECK_GE(abs(metrics.lfMessageFont.lfHeight), 5);
     HFONT font = CreateFontIndirect(&metrics.lfMessageFont);
     DLOG_ASSERT(font);
     base_font_ref_ = ChromeFont::CreateHFontRef(font);
     // base_font_ref_ is global, up the ref count so it's never deleted.
     base_font_ref_->AddRef();
   }
@@ skipping 116 matching lines @@
   }
   if (font_metrics.tmWeight >= kTextMetricWeightBold) {
     style |= ChromeFont::BOLD;
   }
 
   return new HFontRef(font, height, baseline, ave_char_width, style,
                       dlu_base_x);
 }