Add missing SkRect initialization

Author: knopp

flow/layers/physical_shape_layer.cc

@@ -56,7 +56,7 @@ void PhysicalShapeLayer::Preroll(PrerollContext* context,
   Layer::AutoPrerollSaveLayerState save =
       Layer::AutoPrerollSaveLayerState::Create(context, UsesSaveLayer());
 
-  SkRect child_paint_bounds;
+  SkRect child_paint_bounds = SkRect::MakeEmpty();
   PrerollChildren(context, matrix, &child_paint_bounds);
 
   SkRect paint_bounds;

flow/layers/physical_shape_layer_unittests.cc

@@ -87,7 +87,7 @@ TEST_F(PhysicalShapeLayerTest, ChildrenLargerThanPathClip) {
   layer->Add(child1);
   layer->Add(child2);
 
-  SkRect child_paint_bounds;
+  SkRect child_paint_bounds = SkRect::MakeEmpty();
   layer->Preroll(preroll_context(), SkMatrix());
   child_paint_bounds.join(child1->paint_bounds());
   child_paint_bounds.join(child2->paint_bounds());
@@ -142,7 +142,7 @@ TEST_F(PhysicalShapeLayerTest, ChildrenLargerThanPathNoClip) {
   layer->Add(child1);
   layer->Add(child2);
 
-  SkRect total_bounds;
+  SkRect total_bounds = SkRect::MakeEmpty();
   layer->Preroll(preroll_context(), SkMatrix());
   total_bounds.join(child1->paint_bounds());
   total_bounds.join(child2->paint_bounds());