Add heuristic to LayoutTextControl::hasValidAvgCharWidth()

third_party/WebKit/Source/core/layout/LayoutTextControlSingleLine.cpp

 /**
  * Copyright (C) 2006, 2007, 2010 Apple Inc. All rights reserved.
  *           (C) 2008 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 213 matching lines @@
 LayoutUnit LayoutTextControlSingleLine::preferredContentLogicalWidth(float charWidth) const
 {
     int factor;
     bool includesDecoration = inputElement()->sizeShouldIncludeDecoration(factor);
     if (factor <= 0)
         factor = 20;
 
     LayoutUnit result = LayoutUnit::fromFloatCeil(charWidth * factor);
 
     float maxCharWidth = 0.f;
-    AtomicString family = styleRef().font().getFontDescription().family().family();
+    const Font& font = style()->font();
+    AtomicString family = font.getFontDescription().family().family();
     // Match the default system font to the width of MS Shell Dlg, the default
     // font for textareas in Firefox, Safari Win and IE for some encodings (in
     // IE, the default font is encoding specific). 4027 is the (xMax - xMin)
     // value in the "head" font table for MS Shell Dlg.
     if (LayoutTheme::theme().needsHackForTextControlWithFontFamily(family))
         maxCharWidth = scaleEmToUnits(4027);
-    else if (hasValidAvgCharWidth(family))
-        maxCharWidth = roundf(styleRef().font().primaryFont()->maxCharWidth());
+    else if (hasValidAvgCharWidth(font.primaryFont(), family))
+        maxCharWidth = roundf(font.primaryFont()->maxCharWidth());
 
     // For text inputs, IE adds some extra width.
     if (maxCharWidth > 0.f)
         result += maxCharWidth - charWidth;
 
     if (includesDecoration) {
         HTMLElement* spinButton = innerSpinButtonElement();
         if (LayoutBox* spinLayoutObject = spinButton ? spinButton->layoutBox() : 0) {
             result += spinLayoutObject->borderAndPaddingLogicalWidth();
             // Since the width of spinLayoutObject is not calculated yet, spinLayoutObject->logicalWidth() returns 0.
@@ skipping 123 matching lines @@
     // inner-editor element overflows the INPUT box intentionally, however it
     // shouldn't affect outside of the INPUT box.  So we ignore child overflow.
 }
 
 HTMLInputElement* LayoutTextControlSingleLine::inputElement() const
 {
     return toHTMLInputElement(node());
 }
 
 } // namespace blink