Always initialize |m_totalWidth| in HarfBuzzShaper::shape.

R=leviw@chromium.org
BUG=476647

Review URL: https://codereview.chromium.org/1108663003

git-svn-id: svn://svn.chromium.org/blink/trunk@194541 bbb929c8-8fbe-4397-9dbb-9b2b20218538
inline CachedShapingResults* HarfBuzzRunCache::find(const std::wstring& key) const
{
    CachedShapingResultsMap::const_iterator it = m_harfBuzzRunMap.find(key);

    return it != m_harfBuzzRunMap.end() ? it->second : 0;
}

inline CachedShapingResults* HarfBuzzRunCache::find(const std::wstring& key) const
{
    CachedShapingResultsMap::const_iterator it = m_harfBuzzRunMap.find(key);

    return it != m_harfBuzzRunMap.end() ? it->second : 0;
}
