bug 693610 - accumulate advanceSum so that we don't overlap successive glyph runs when drawing text to azure canvas. r=bas

content/canvas/src/nsCanvasRenderingContext2DAzure.cpp

@@ -3066,6 +3066,8 @@ struct NS_STACK_CLASS nsCanvasBidiProcessorAzure : public nsBidiPresUtils::BidiP
     Point baselineOrigin =
       Point(point.x * devUnitsPerAppUnit, point.y * devUnitsPerAppUnit);
 
+    float advanceSum = 0;
+
     for (PRUint32 c = 0; c < numRuns; c++) {
       gfxFont *font = runs[c].mFont;
       PRUint32 endRun = 0;
@@ -3084,8 +3086,6 @@ struct NS_STACK_CLASS nsCanvasBidiProcessorAzure : public nsBidiPresUtils::BidiP
 
       std::vector<Glyph> glyphBuf;
 
-      float advanceSum = 0;
-
       for (PRUint32 i = runs[c].mCharacterOffset; i < endRun; i++) {
         Glyph newGlyph;
         if (glyphs[i].IsSimpleGlyph()) {