Fix undefined behavior in DirectWrite GDI compatible metrics. GetGdiCompatibleGlyphMetrics checks the matrix passed to it. If the matrix has any NaNs or INFs or otherwise looks bad, it returns E_INVALIDARG and so the advances will be zero. BUG=skia:2579 [email protected] Review URL: https://codereview.chromium.org/298863002 git-svn-id: http://skia.googlecode.com/svn/trunk/src@14829 2bbb7eff-a529-9590-31e7-b0007b416f81