Improve print preview checks in the PDF plugin

pdf/out_of_process_instance.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 PDF_OUT_OF_PROCESS_INSTANCE_H_
 #define PDF_OUT_OF_PROCESS_INSTANCE_H_
 
 #include <stdint.h>
 #include <string.h>
 
@@ skipping 353 matching lines @@
   int top_toolbar_height_;
 
   // The current state of accessibility: either off, enabled but waiting
   // for the document to load, or fully loaded.
   enum AccessibilityState {
     ACCESSIBILITY_STATE_OFF,
     ACCESSIBILITY_STATE_PENDING,  // Enabled but waiting for doc to load.
     ACCESSIBILITY_STATE_LOADED
   } accessibility_state_;
 
+  // True if the plugin is loaded in print preview, otherwise false.
+  bool is_print_preview_;
+
   DISALLOW_COPY_AND_ASSIGN(OutOfProcessInstance);
 };
 
 }  // namespace chrome_pdf
 
 #endif  // PDF_OUT_OF_PROCESS_INSTANCE_H_