C++11 declares a type safe null pointer

content/common/gpu/client/gpu_memory_buffer_impl_surface_texture.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/common/gpu/client/gpu_memory_buffer_impl_surface_texture.h"
 
 #include "base/atomic_sequence_num.h"
 #include "base/bind.h"
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
@@ skipping 145 matching lines @@
       return 0;
   }
 }
 
 void* GpuMemoryBufferImplSurfaceTexture::Map() {
   TRACE_EVENT0("gpu", "GpuMemoryBufferImplSurfaceTexture::Map");
 
   DCHECK(!mapped_);
   DCHECK(native_window_);
   ANativeWindow_Buffer buffer;
-  int status = ANativeWindow_lock(native_window_, &buffer, NULL);
+  int status = ANativeWindow_lock(native_window_, &buffer, nullptr);
   if (status) {
     VLOG(1) << "ANativeWindow_lock failed with error code: " << status;
-    return NULL;
+    return nullptr;
   }
 
   DCHECK_LE(size_.width(), buffer.stride);
   stride_ = buffer.stride * BytesPerPixel(internalformat_);
   mapped_ = true;
   return buffer.bits;
 }
 
 void GpuMemoryBufferImplSurfaceTexture::Unmap() {
   TRACE_EVENT0("gpu", "GpuMemoryBufferImplSurfaceTexture::Unmap");
 
   DCHECK(mapped_);
   ANativeWindow_unlockAndPost(native_window_);
   mapped_ = false;
 }
 
 uint32 GpuMemoryBufferImplSurfaceTexture::GetStride() const { return stride_; }
 
 gfx::GpuMemoryBufferHandle GpuMemoryBufferImplSurfaceTexture::GetHandle()
     const {
   gfx::GpuMemoryBufferHandle handle;
   handle.type = gfx::SURFACE_TEXTURE_BUFFER;
   handle.global_id = id_;
   return handle;
 }
 
 }  // namespace content