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

core/src/fpdfdoc/doc_annot.cpp

Index: core/src/fpdfdoc/doc_annot.cpp
diff --git a/core/src/fpdfdoc/doc_annot.cpp b/core/src/fpdfdoc/doc_annot.cpp
index 9bef7ccda29194620056b5fc088fcbb898a76392..623bb011cd9f905f9a8012ad43da23977aeb9baa 100644
--- a/core/src/fpdfdoc/doc_annot.cpp
+++ b/core/src/fpdfdoc/doc_annot.cpp
@@ -137,7 +137,7 @@ CFX_ByteString CPDF_Annot::GetSubType() const {
 }
 
 void CPDF_Annot::GetRect(CPDF_Rect& rect) const {
-  if (m_pAnnotDict == NULL) {
+  if (!m_pAnnotDict) {
     return;
   }
   rect = m_pAnnotDict->GetRect("Rect");
@@ -151,7 +151,7 @@ FX_DWORD CPDF_Annot::GetFlags() const {
 CPDF_Stream* FPDFDOC_GetAnnotAP(CPDF_Dictionary* pAnnotDict,
                                 CPDF_Annot::AppearanceMode mode) {
   CPDF_Dictionary* pAP = pAnnotDict->GetDict("AP");
-  if (pAP == NULL) {
+  if (!pAP) {
     return NULL;
   }
   const FX_CHAR* ap_entry = "N";
@@ -271,14 +271,14 @@ void CPDF_Annot::DrawBorder(CFX_RenderDevice* pDevice,
   char style_char;
   FX_FLOAT width;
   CPDF_Array* pDashArray = NULL;
-  if (pBS == NULL) {
+  if (!pBS) {
     CPDF_Array* pBorderArray = m_pAnnotDict->GetArray("Border");
     style_char = 'S';
     if (pBorderArray) {
       width = pBorderArray->GetNumber(2);
       if (pBorderArray->GetCount() == 4) {
         pDashArray = pBorderArray->GetArray(3);
-        if (pDashArray == NULL) {
+        if (!pDashArray) {
           return;
         }
         int nLen = pDashArray->GetCount();