fix null check bugs found by µmix static analyzer

src/utils/win/SkDWriteFontFileStream.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #include "SkTypes.h"
 #if defined(SK_BUILD_FOR_WIN32)
 
 #include "SkTypes.h"
@@ skipping 121 matching lines @@
     return fLockedMemory;
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 //  SkIDWriteFontFileStreamWrapper
 
 HRESULT SkDWriteFontFileStreamWrapper::Create(SkStreamAsset* stream,
                                               SkDWriteFontFileStreamWrapper** streamFontFileStream)
 {
     *streamFontFileStream = new SkDWriteFontFileStreamWrapper(stream);
-    if (nullptr == streamFontFileStream) {
+    if (nullptr == *streamFontFileStream) {

[reed1, 2016/06/08 10:35:10]

We NEVER assume 'new' will return nullptr. Can we remove this check?

         return E_OUTOFMEMORY;
     }
     return S_OK;
 }
 
 SkDWriteFontFileStreamWrapper::SkDWriteFontFileStreamWrapper(SkStreamAsset* stream)
     : fRefCount(1), fStream(stream) {
 }
 
 HRESULT STDMETHODCALLTYPE SkDWriteFontFileStreamWrapper::QueryInterface(REFIID iid, void** ppvObject) {
@@ skipping 73 matching lines @@
     return S_OK;
 }
 
 HRESULT STDMETHODCALLTYPE SkDWriteFontFileStreamWrapper::GetLastWriteTime(UINT64* lastWriteTime) {
     // The concept of last write time does not apply to this loader.
     *lastWriteTime = 0;
     return E_NOTIMPL;
 }
 
 #endif//defined(SK_BUILD_FOR_WIN32)