Bug 1910815 - Inflate glyph bounds to account for potential font hinting. r=aosmond

Differential Revision: https://phabricator.services.mozilla.com/D219403

dom/canvas/DrawTargetWebgl.cpp

@@ -4301,7 +4301,7 @@ bool SharedContextWebgl::DrawGlyphsAccel(ScaledFont* aFont,
     if (xformBounds.IsEmpty()) {
       return true;
     }
-    IntRect fullBounds = RoundedOut(currentTransform.TransformBounds(*bounds));
+    IntRect fullBounds = RoundedOut(xformBounds);
     IntRect clipBounds = fullBounds.Intersect(clipRect);
     // Check if the bounds are completely clipped out.
     if (clipBounds.IsEmpty()) {

gfx/2d/DrawTargetSkia.cpp

@@ -1430,6 +1430,8 @@ Maybe<Rect> DrawTargetSkia::GetGlyphLocalBounds(
     return Nothing();
   }
 
+  // Inflate the bounds to account for potential font hinting.
+  bounds.Inflate(1);
   return Some(bounds);
 }