Remove code that checks GetSystemHandler() return value.

GetSystemHandler() never returns nullptr. Fix some nits along the way.

Change-Id: I6003053fa2d23d887f94e24a5fab8a26b1d50555
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/58812
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
diff --git a/fpdfsdk/pwl/cpwl_edit.cpp b/fpdfsdk/pwl/cpwl_edit.cpp
index 6ce6a0f..99fe2c2 100644
--- a/fpdfsdk/pwl/cpwl_edit.cpp
+++ b/fpdfsdk/pwl/cpwl_edit.cpp
@@ -172,7 +172,7 @@
     switch (GetBorderStyle()) {
       case BorderStyle::SOLID: {
         CFX_GraphStateData gsd;
-        gsd.m_LineWidth = (float)GetBorderWidth();
+        gsd.m_LineWidth = GetBorderWidth();
 
         CFX_PathData path;
 
@@ -237,10 +237,9 @@
     pRange = &wrRange;
   }
 
-  IPWL_SystemHandler* pSysHandler = GetSystemHandler();
   CPWL_EditImpl::DrawEdit(pDevice, mtUser2Device, m_pEdit.get(),
                           GetTextColor().ToFXColor(GetTransparency()), rcClip,
-                          CFX_PointF(), pRange, pSysHandler,
+                          CFX_PointF(), pRange, GetSystemHandler(),
                           m_pFormFiller.Get());
 }
 
@@ -279,10 +278,6 @@
   if (!HasFlag(PES_TEXTOVERFLOW) && !ClientHitTest(point))
     return true;
 
-  IPWL_SystemHandler* pSH = GetSystemHandler();
-  if (!pSH)
-    return false;
-
   SetFocus();
 
   return false;
diff --git a/fpdfsdk/pwl/cpwl_edit_impl.cpp b/fpdfsdk/pwl/cpwl_edit_impl.cpp
index 6197dd7..0705478 100644
--- a/fpdfsdk/pwl/cpwl_edit_impl.cpp
+++ b/fpdfsdk/pwl/cpwl_edit_impl.cpp
@@ -498,7 +498,7 @@
       bSelect = place > wrSelect.BeginPos && place <= wrSelect.EndPos;
       crCurFill = bSelect ? crWhite : crTextFill;
     }
-    if (pSystemHandler && pSystemHandler->IsSelectionImplemented()) {
+    if (pSystemHandler->IsSelectionImplemented()) {
       crCurFill = crTextFill;
       crOldFill = crCurFill;
     }
@@ -508,7 +508,7 @@
         CPVT_Line line;
         pIterator->GetLine(line);
 
-        if (pSystemHandler && pSystemHandler->IsSelectionImplemented()) {
+        if (pSystemHandler->IsSelectionImplemented()) {
           CFX_FloatRect rc(word.ptWord.x, line.ptLine.y + line.fLineDescent,
                            word.ptWord.x + word.fWidth,
                            line.ptLine.y + line.fLineAscent);
diff --git a/fpdfsdk/pwl/cpwl_list_box.cpp b/fpdfsdk/pwl/cpwl_list_box.cpp
index b64b4a0..f6f7201 100644
--- a/fpdfsdk/pwl/cpwl_list_box.cpp
+++ b/fpdfsdk/pwl/cpwl_list_box.cpp
@@ -107,15 +107,13 @@
     CFX_PointF ptOffset(rcItem.left, (rcItem.top + rcItem.bottom) * 0.5f);
     if (CPWL_EditImpl* pEdit = m_pList->GetItemEdit(i)) {
       CFX_FloatRect rcContent = pEdit->GetContentRect();
-      if (rcContent.Width() > rcClient.Width())
-        rcItem.Intersect(rcList);
-      else
-        rcItem.Intersect(rcClient);
+      rcItem.Intersect(rcContent.Width() > rcClient.Width() ? rcList
+                                                            : rcClient);
     }
 
     IPWL_SystemHandler* pSysHandler = GetSystemHandler();
     if (m_pList->IsItemSelected(i)) {
-      if (pSysHandler && pSysHandler->IsSelectionImplemented()) {
+      if (pSysHandler->IsSelectionImplemented()) {
         CPWL_EditImpl::DrawEdit(pDevice, mtUser2Device, m_pList->GetItemEdit(i),
                                 GetTextColor().ToFXColor(255), rcList, ptOffset,
                                 nullptr, pSysHandler, m_pFormFiller.Get());
diff --git a/fpdfsdk/pwl/cpwl_wnd.cpp b/fpdfsdk/pwl/cpwl_wnd.cpp
index d2daa9c..0b77ee4 100644
--- a/fpdfsdk/pwl/cpwl_wnd.cpp
+++ b/fpdfsdk/pwl/cpwl_wnd.cpp
@@ -269,15 +269,11 @@
   rcWin.Inflate(1, 1);
   rcWin.Normalize();
 
-  IPWL_SystemHandler* pSH = GetSystemHandler();
-  if (!pSH)
-    return true;
-
   CPDFSDK_Widget* widget = m_pAttachedData->GetWidget();
   if (!widget)
     return true;
 
-  pSH->InvalidateRect(widget, rcWin);
+  GetSystemHandler()->InvalidateRect(widget, rcWin);
   return !!thisObserved;
 }
 
@@ -605,10 +601,8 @@
 void CPWL_Wnd::CreateChildWnd(const CreateParams& cp) {}
 
 void CPWL_Wnd::SetCursor() {
-  if (IsValid()) {
-    if (IPWL_SystemHandler* pSH = GetSystemHandler())
-      pSH->SetCursor(GetCreationParams()->eCursorType);
-  }
+  if (IsValid())
+    GetSystemHandler()->SetCursor(GetCreationParams()->eCursorType);
 }
 
 void CPWL_Wnd::CreateMsgControl() {