Check if temp file was created before OnPageDone called

chrome/browser/printing/pdf_to_emf_converter.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 "chrome/browser/printing/pdf_to_emf_converter.h"
 
 #include <queue>
 
 #include "base/files/file.h"
 #include "base/files/file_util.h"
@@ skipping 42 matching lines @@
 typedef scoped_ptr<base::File, BrowserThread::DeleteOnFileThread>
     ScopedTempFile;
 
 // Wrapper for Emf to keep only file handle in memory, and load actual data only
 // on playback. Emf::InitFromFile() can play metafile directly from disk, but it
 // can't open file handles. We need file handles to reliably delete temporary
 // files, and to efficiently interact with utility process.
 class LazyEmf : public MetafilePlayer {
  public:
   LazyEmf(const scoped_refptr<RefCountedTempDir>& temp_dir, ScopedTempFile file)
-      : temp_dir_(temp_dir), file_(file.Pass()) {}
+      : temp_dir_(temp_dir), file_(file.Pass()) {
+    CHECK(file_);
+  }
   ~LazyEmf() override { Close(); }
 
   bool SafePlayback(HDC hdc) const override;
   bool SaveTo(base::File* file) const override;
 
  private:
   void Close() const;
   bool LoadEmf(Emf* emf) const;
 
   mutable scoped_refptr<RefCountedTempDir> temp_dir_;
@@ skipping 52 matching lines @@
       page_number_ = rhs.object->page_number_;
       callback_ = rhs.object->callback_;
       emf_ = rhs.object->emf_.Pass();
       return *this;
     }
 
     int page_number() const { return page_number_; }
     const PdfToEmfConverter::GetPageCallback& callback() const {
       return callback_;
     }
-    ScopedTempFile emf() { return emf_.Pass(); }
+    ScopedTempFile TakeEmf() { return emf_.Pass(); }
     void set_emf(ScopedTempFile emf) { emf_ = emf.Pass(); }
 
    private:
     int page_number_;
     PdfToEmfConverter::GetPageCallback callback_;
     ScopedTempFile emf_;
   };
 
   ~PdfToEmfUtilityProcessHostClient() override;
 
@@ skipping 244 matching lines @@
   // Should reply with OnPageDone().
   Send(new ChromeUtilityMsg_RenderPDFPagesToMetafiles_GetPage(
       callback_data->page_number(), transit));
 }
 
 void PdfToEmfUtilityProcessHostClient::OnPageDone(bool success,
                                                   float scale_factor) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   if (get_page_callbacks_.empty())
     return OnFailed();
+  GetPageCallbackData& data = get_page_callbacks_.front();
   scoped_ptr<MetafilePlayer> emf;
-  GetPageCallbackData& data = get_page_callbacks_.front();
-  if (success)
-    emf.reset(new LazyEmf(temp_dir_, data.emf().Pass()));
+
+  if (success) {
+    ScopedTempFile temp_emf = data.TakeEmf();
+    if (!temp_emf)  // Unexpected message from utility process.
+      return OnFailed();
+    emf.reset(new LazyEmf(temp_dir_, temp_emf.Pass()));
+  }
+
   BrowserThread::PostTask(BrowserThread::UI,
                           FROM_HERE,
                           base::Bind(&PdfToEmfConverterImpl::RunCallback,
                                      converter_,
                                      base::Bind(data.callback(),
                                                 data.page_number(),
                                                 scale_factor,
                                                 base::Passed(&emf))));
   get_page_callbacks_.pop();
 }
@@ skipping 79 matching lines @@
 
 PdfToEmfConverter::~PdfToEmfConverter() {
 }
 
 // static
 scoped_ptr<PdfToEmfConverter> PdfToEmfConverter::CreateDefault() {
   return scoped_ptr<PdfToEmfConverter>(new PdfToEmfConverterImpl());
 }
 
 }  // namespace printing