Make CPDFSDK_PageView::GetCurrentMatrix() a normal getter.

Return the matrix instead of setting an out parameter. Simplify callers
along the way.

Change-Id: Ia9b64c06a9cdab0d0a020c4c99d1a76e98ffc007
Reviewed-on: https://pdfium-review.googlesource.com/c/47430
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
diff --git a/fpdfsdk/cfx_systemhandler.cpp b/fpdfsdk/cfx_systemhandler.cpp
index fae3282..42d1970 100644
--- a/fpdfsdk/cfx_systemhandler.cpp
+++ b/fpdfsdk/cfx_systemhandler.cpp
@@ -35,11 +35,7 @@
   if (!pPage || !pPageView)
     return;
 
-  CFX_Matrix page2device;
-  pPageView->GetCurrentMatrix(page2device);
-
-  CFX_Matrix device2page = page2device.GetInverse();
-
+  CFX_Matrix device2page = pPageView->GetCurrentMatrix().GetInverse();
   CFX_PointF left_top = device2page.Transform(CFX_PointF(rect.left, rect.top));
   CFX_PointF right_bottom =
       device2page.Transform(CFX_PointF(rect.right, rect.bottom));
diff --git a/fpdfsdk/cpdfsdk_pageview.h b/fpdfsdk/cpdfsdk_pageview.h
index c3cbbc6..d877a70 100644
--- a/fpdfsdk/cpdfsdk_pageview.h
+++ b/fpdfsdk/cpdfsdk_pageview.h
@@ -82,7 +82,7 @@
                     const CFX_PointF& point,
                     int nFlag);
 
-  void GetCurrentMatrix(CFX_Matrix& matrix) { matrix = m_curMatrix; }
+  const CFX_Matrix& GetCurrentMatrix() const { return m_curMatrix; }
   void UpdateRects(const std::vector<CFX_FloatRect>& rects);
   void UpdateView(CPDFSDK_Annot* pAnnot);
 
diff --git a/fpdfsdk/cpdfsdk_widget.cpp b/fpdfsdk/cpdfsdk_widget.cpp
index c3e1eb9..377e068 100644
--- a/fpdfsdk/cpdfsdk_widget.cpp
+++ b/fpdfsdk/cpdfsdk_widget.cpp
@@ -673,9 +673,7 @@
   if (!m_pInteractiveForm->IsNeedHighLight(fieldType))
     return;
 
-  CFX_Matrix page2device;
-  pPageView->GetCurrentMatrix(page2device);
-
+  CFX_Matrix page2device = pPageView->GetCurrentMatrix();
   CFX_FloatRect rcDevice = GetRect();
   CFX_PointF tmp =
       page2device.Transform(CFX_PointF(rcDevice.left, rcDevice.bottom));
diff --git a/fpdfsdk/formfiller/cffl_formfiller.cpp b/fpdfsdk/formfiller/cffl_formfiller.cpp
index 91e16e8..50787b2 100644
--- a/fpdfsdk/formfiller/cffl_formfiller.cpp
+++ b/fpdfsdk/formfiller/cffl_formfiller.cpp
@@ -424,10 +424,8 @@
   if (!pPrivateData || !pPrivateData->pPageView)
     return mt;
 
-  CFX_Matrix mtPageView;
-  pPrivateData->pPageView->GetCurrentMatrix(mtPageView);
   mt = GetCurMatrix();
-  mt.Concat(mtPageView);
+  mt.Concat(pPrivateData->pPageView->GetCurrentMatrix());
   return mt;
 }