Remove unsafe getFontMetrics methods

third_party/WebKit/Source/core/style/ComputedStyle.h

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All
  * rights reserved.
  * Copyright (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 2496 matching lines @@
   EUserSelect userSelect() const {
     return static_cast<EUserSelect>(m_rareInheritedData->userSelect);
   }
   void setUserSelect(EUserSelect s) {
     SET_VAR(m_rareInheritedData, userSelect, s);
   }
 
   // Font properties.
   const Font& font() const;
   void setFont(const Font&);
-  const FontMetrics& getFontMetrics() const;

[wkorman, 2016/10/13 22:54:30]

Discussed in person -- an alternative approach that would save on code verbosity
at callsites could be to have something like a final-fallback dummy
PrimaryFont/FontMetrics that is implemented purely in code and returns
equivalent of zero/empty values, and return that here if we failed to load even
the single final fallback font. And then, add a separate method callsites can
use to check explicitly whether there's a real font available for retrieving
metrics or we've had to fall back to the dummy case.

However, we'd like to try this change as written for now. The above could lead
to new code not being written in a thoughtful manner, and so having a pointer
where it's clear it could be null will require authors to consider this case.

   const FontDescription& getFontDescription() const;
   bool setFontDescription(const FontDescription&);
   bool hasIdenticalAscentDescentAndLineGap(const ComputedStyle& other) const;
 
   // font-size
   int fontSize() const;
   float specifiedFontSize() const;
   float computedFontSize() const;
 
   // font-size-adjust
@@ skipping 1583 matching lines @@
   m_nonInheritedData.m_pseudoBits |= 1 << (pseudo - 1);
 }
 
 inline bool ComputedStyle::hasPseudoElementStyle() const {
   return m_nonInheritedData.m_pseudoBits & ElementPseudoIdMask;
 }
 
 }  // namespace blink
 
 #endif  // ComputedStyle_h