Instead of ArrayBuffer, pass blob with printerProvider.onPrintRequested

content/browser/fileapi/chrome_blob_storage_context.h

 // Copyright (c) 2012 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.
 
 #ifndef CONTENT_BROWSER_FILEAPI_CHROME_BLOB_STORAGE_CONTEXT_H_
 #define CONTENT_BROWSER_FILEAPI_CHROME_BLOB_STORAGE_CONTEXT_H_
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/sequenced_task_runner_helpers.h"
 #include "content/common/content_export.h"
 
+namespace base {
+class FilePath;
+class Time;
+}
+
 namespace storage {
 class BlobStorageContext;
 }
 
 namespace content {
 class BlobHandle;
 class BrowserContext;
 struct ChromeBlobStorageContextDeleter;
 
 // A context class that keeps track of BlobStorageController used by the chrome.
@@ skipping 13 matching lines @@
       BrowserContext* browser_context);
 
   void InitializeOnIOThread();
 
   storage::BlobStorageContext* context() const { return context_.get(); }
 
   // Returns a NULL scoped_ptr on failure.
   scoped_ptr<BlobHandle> CreateMemoryBackedBlob(const char* data,
                                                 size_t length);
 
+  // Returns a NULL scoped_ptr on failure.
+  scoped_ptr<BlobHandle> CreateFileBackedBlob(
+      const base::FilePath& path,
+      int64_t offset,
+      int64_t size,
+      const base::Time& expected_modification_time);
+
  protected:
   virtual ~ChromeBlobStorageContext();
 
  private:
   friend class base::DeleteHelper<ChromeBlobStorageContext>;
   friend class base::RefCountedThreadSafe<ChromeBlobStorageContext,
                                           ChromeBlobStorageContextDeleter>;
   friend struct ChromeBlobStorageContextDeleter;
 
   void DeleteOnCorrectThread() const;
 
   scoped_ptr<storage::BlobStorageContext> context_;
 };
 
 struct ChromeBlobStorageContextDeleter {
   static void Destruct(const ChromeBlobStorageContext* context) {
     context->DeleteOnCorrectThread();
   }
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_FILEAPI_CHROME_BLOB_STORAGE_CONTEXT_H_