Always initialize |m_totalWidth| in HarfBuzzShaper::shape.

Source/platform/fonts/shaping/HarfBuzzShaper.cpp

 /*
  * Copyright (c) 2012 Google Inc. All rights reserved.
  * Copyright (C) 2013 BlackBerry Limited. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 520 matching lines @@
         feature.tag = HB_TAG(tag[0], tag[1], tag[2], tag[3]);
         feature.value = settings->at(i).value();
         feature.start = 0;
         feature.end = static_cast<unsigned>(-1);
         m_features.append(feature);
     }
 }
 
 bool HarfBuzzShaper::shape(GlyphBuffer* glyphBuffer)
 {
+    m_totalWidth = 0;

[Daniel Erat, 2015/04/27 15:42:21]

mind initializing it in the c'tor as well? having uninitialized members hanging
around makes me nervous.

     if (!createHarfBuzzRuns())
         return false;
 
-    m_totalWidth = 0;
     if (!shapeHarfBuzzRuns())
         return false;
 
     if (glyphBuffer && !fillGlyphBuffer(glyphBuffer))
         return false;
 
     return true;
 }
 
 struct CandidateRun {
@@ skipping 651 matching lines @@
     // possibly invalid from, to arguments.
     if (!foundToX && !foundFromX)
         fromX = toX = 0;
 
     if (fromX < toX)
         return FloatRect(point.x() + fromX, point.y(), toX - fromX, height);
     return FloatRect(point.x() + toX, point.y(), fromX - toX, height);
 }
 
 } // namespace blink