Bug 1035330 - Optimize rects in the gfxContext methods for getting extents to fix tsvgr_opacity regressions. r=Bas

gfx/thebes/gfxContext.cpp

@@ -1769,6 +1769,9 @@ gfxContext::GetUserPathExtent()
     cairo_path_extents(mCairo, &xmin, &ymin, &xmax, &ymax);
     return gfxRect(xmin, ymin, xmax - xmin, ymax - ymin);
   } else {
+    if (mPathIsRect) {
+      return ThebesRect(mTransform.TransformBounds(mRect));
+    }
     EnsurePath();
     return ThebesRect(mPath->GetBounds());
   }
@@ -1782,6 +1785,9 @@ gfxContext::GetUserFillExtent()
     cairo_fill_extents(mCairo, &xmin, &ymin, &xmax, &ymax);
     return gfxRect(xmin, ymin, xmax - xmin, ymax - ymin);
   } else {
+    if (mPathIsRect) {
+      return ThebesRect(mTransform.TransformBounds(mRect));
+    }
     EnsurePath();
     return ThebesRect(mPath->GetBounds());
   }
@@ -1795,6 +1801,11 @@ gfxContext::GetUserStrokeExtent()
     cairo_stroke_extents(mCairo, &xmin, &ymin, &xmax, &ymax);
     return gfxRect(xmin, ymin, xmax - xmin, ymax - ymin);
   } else {
+    if (mPathIsRect) {
+      Rect rect = mRect;
+      rect.Inflate(CurrentState().strokeOptions.mLineWidth / 2);
+      return ThebesRect(mTransform.TransformBounds(rect));
+    }
     EnsurePath();
     return ThebesRect(mPath->GetStrokedBounds(CurrentState().strokeOptions, mTransform));
   }