Get rid of getCTM/setCTM pair in Font::paintGlyphsVertical

Source/platform/graphics/GraphicsContextStateSaver.h

 // Copyright (C) 2013 Google Inc. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //    * Redistributions of source code must retain the above copyright
 // notice, this list of conditions and the following disclaimer.
 //    * Redistributions in binary form must reproduce the above
 // copyright notice, this list of conditions and the following disclaimer
@@ skipping 62 matching lines @@
     }
 
     GraphicsContext* context() const { return &m_context; }
     bool saved() const { return m_saveAndRestore; }
 
 private:
     GraphicsContext& m_context;
     bool m_saveAndRestore;
 };
 
+class GraphicsContextCTMSaver {
+public:
+    GraphicsContextCTMSaver(GraphicsContext& context)
+        : m_canvas(context.contextDisabled() ? nullptr : context.canvas())
+    {
+        if (m_canvas)
+            m_savedMatrix = m_canvas->getTotalMatrix();
+    }
+
+    ~GraphicsContextCTMSaver()
+    {
+        if (m_canvas)
+            m_canvas->setMatrix(m_savedMatrix);
+    }
+
+private:
+    SkMatrix m_savedMatrix;
+    SkCanvas* m_canvas;
+};
+
 } // namespace blink
 
 #endif // GraphicsContextStateSaver_h