Get rid of most instance of 'foo == NULL'

core/src/fxge/ge/fx_ge_device.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 "core/include/fxge/fx_ge.h"
 
 CFX_RenderDevice::CFX_RenderDevice() {
   m_pDeviceDriver = NULL;
@@ skipping 112 matching lines @@
   if (FXGETFLAG_COLORTYPE(alpha_flag)) {
     fill_alpha = FXGETFLAG_ALPHA_FILL(alpha_flag);
     stroke_alpha = FXGETFLAG_ALPHA_STROKE(alpha_flag);
   } else {
     fill_alpha = FXARGB_A(fill_color);
     stroke_alpha = FXARGB_A(stroke_color);
   }
   if ((fill_mode & 3) == 0) {
     fill_alpha = 0;
   }
-  if (pGraphState == NULL) {
+  if (!pGraphState) {
     stroke_alpha = 0;
   }
   if (stroke_alpha == 0 && pPathData->GetPointCount() == 2) {
     FX_PATHPOINT* pPoints = pPathData->GetPoints();
     FX_FLOAT x1, x2, y1, y2;
     if (pObject2Device) {
       pObject2Device->Transform(pPoints[0].m_PointX, pPoints[0].m_PointY, x1,
                                 y1);
       pObject2Device->Transform(pPoints[1].m_PointX, pPoints[1].m_PointY, x2,
                                 y2);
@@ skipping 321 matching lines @@
   return m_pDeviceDriver->StartDIBits(pBitmap, bitmap_alpha, argb, pMatrix,
                                       flags, handle, alpha_flag, pIccTransform,
                                       blend_mode);
 }
 FX_BOOL CFX_RenderDevice::ContinueDIBits(void* handle, IFX_Pause* pPause) {
   return m_pDeviceDriver->ContinueDIBits(handle, pPause);
 }
 void CFX_RenderDevice::CancelDIBits(void* handle) {
   m_pDeviceDriver->CancelDIBits(handle);
 }