Fix more bugs found by /analyze tool

xfa/fwl/core/cfwl_widgetmgr.cpp

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include "xfa/fwl/core/cfwl_widgetmgr.h"
 
 #include "xfa/fwl/core/cfwl_message.h"
 #include "xfa/fwl/core/fwl_appimp.h"
@@ skipping 750 matching lines @@
   if (!pChild)
     return TRUE;
 
   CFX_RectF rtChilds;
   rtChilds.Empty();
   FX_BOOL bChildIntersectWithDirty = FALSE;
   FX_BOOL bOrginPtIntersectWidthChild = FALSE;
   FX_BOOL bOrginPtIntersectWidthDirty =
       rtDirty.Contains(rtWidget.left, rtWidget.top);
   static FWL_NEEDREPAINTHITDATA hitPoint[kNeedRepaintHitPoints];
-  int32_t iSize = sizeof(FWL_NEEDREPAINTHITDATA);
-  FXSYS_memset(hitPoint, 0, iSize);
+  FXSYS_memset(hitPoint, 0,
+               sizeof(FWL_NEEDREPAINTHITDATA) * kNeedRepaintHitPoints);

[Tom Sepez, 2016/06/03 18:54:37]

just sizeof(hitPoint)

[Wei Li, 2016/06/03 19:48:21]

Done.

This one is a real bug too, hitPoint's content such as bNotContainByDirty was
used without be initialized. The
state is unknown. 

   FX_FLOAT fxPiece = rtWidget.width / kNeedRepaintHitPiece;
   FX_FLOAT fyPiece = rtWidget.height / kNeedRepaintHitPiece;
   hitPoint[2].hitPoint.x = hitPoint[6].hitPoint.x = rtWidget.left;
   hitPoint[0].hitPoint.x = hitPoint[3].hitPoint.x = hitPoint[7].hitPoint.x =
       hitPoint[10].hitPoint.x = fxPiece + rtWidget.left;
   hitPoint[1].hitPoint.x = hitPoint[4].hitPoint.x = hitPoint[8].hitPoint.x =
       hitPoint[11].hitPoint.x = fxPiece * 2 + rtWidget.left;
   hitPoint[5].hitPoint.x = hitPoint[9].hitPoint.x =
       rtWidget.width + rtWidget.left;
   hitPoint[0].hitPoint.y = hitPoint[1].hitPoint.y = rtWidget.top;
@@ skipping 70 matching lines @@
     temp.Deflate(50, 50);
     if (!temp.Contains(r))
       return FALSE;
 
     pItem->bOutsideChanged = FALSE;
   }
 #endif
 
   return pItem->iRedrawCounter == 0;
 }