Change CXFA_FFWidget::RenderWidget() to take a const CFX_Matrix&.

Change some related code to take a const CFX_Matrix* since it is not
immediately obvious if the matrix can be made into a const-ref.

Change-Id: I15c840222b575cc479b1f6f0b6d3b3c0e50d5515
Reviewed-on: https://pdfium-review.googlesource.com/11113
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: dsinclair <dsinclair@chromium.org>
diff --git a/fpdfsdk/cpdfsdk_xfawidgethandler.cpp b/fpdfsdk/cpdfsdk_xfawidgethandler.cpp
index e7bf702..e9c9972 100644
--- a/fpdfsdk/cpdfsdk_xfawidgethandler.cpp
+++ b/fpdfsdk/cpdfsdk_xfawidgethandler.cpp
@@ -60,7 +60,7 @@
   if (pPageView->GetFormFillEnv()->GetFocusAnnot() != pAnnot)
     bIsHighlight = true;
 
-  GetXFAWidgetHandler(pAnnot)->RenderWidget(pAnnot->GetXFAWidget(), &gs, &mt,
+  GetXFAWidgetHandler(pAnnot)->RenderWidget(pAnnot->GetXFAWidget(), &gs, mt,
                                             bIsHighlight);
 
   // to do highlight and shadow