Refactor PDFiumEngine::SelectionChangeInvalidator.

pdf/pdfium/pdfium_engine.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_PDFIUM_PDFIUM_ENGINE_H_
 #define PDF_PDFIUM_PDFIUM_ENGINE_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 117 matching lines @@
   // This helper class is used to detect the difference in selection between
   // construction and destruction.  At destruction, it invalidates all the
   // parts that are newly selected, along with all the parts that used to be
   // selected but are not anymore.
   class SelectionChangeInvalidator {
    public:
     explicit SelectionChangeInvalidator(PDFiumEngine* engine);
     ~SelectionChangeInvalidator();
 
    private:
-    // Sets the given container to the all the currently visible selection
-    // rectangles, in screen coordinates.
-    void GetVisibleSelectionsScreenRects(std::vector<pp::Rect>* rects);
+    // Returns all the currently visible selection rectangles, in screen
+    // coordinates.
+    std::vector<pp::Rect> GetVisibleSelections() const;
 
-    PDFiumEngine* engine_;
+    PDFiumEngine* const engine_;
+    // The origin at the time this object was constructed.
+    const pp::Point previous_origin_;
     // Screen rectangles that were selected on construction.
     std::vector<pp::Rect> old_selections_;
-    // The origin at the time this object was constructed.
-    pp::Point previous_origin_;
   };
 
   // Used to store mouse down state to handle it in other mouse event handlers.
   class MouseDownState {
    public:
     MouseDownState(const PDFiumPage::Area& area,
                    const PDFiumPage::LinkTarget& target);
     ~MouseDownState();
 
     void Set(const PDFiumPage::Area& area,
@@ skipping 653 matching lines @@
   bool GetPDFPageSizeByIndex(const void* pdf_buffer,
                              int pdf_buffer_size,
                              int page_number,
                              double* width,
                              double* height) override;
 };
 
 }  // namespace chrome_pdf
 
 #endif  // PDF_PDFIUM_PDFIUM_ENGINE_H_