[WIP: not for review] Reduce re-layout

ui/views/examples/multiline_example.h

Index: ui/views/examples/multiline_example.h
diff --git a/ui/views/examples/multiline_example.h b/ui/views/examples/multiline_example.h
index a4c3ba56ea0d3de17867b20677d2cc3eb56e0307..10d13409b1baa0537d902c817c875294f7096473 100644
--- a/ui/views/examples/multiline_example.h
+++ b/ui/views/examples/multiline_example.h
@@ -10,6 +10,10 @@
 #include "ui/views/controls/textfield/textfield_controller.h"
 #include "ui/views/examples/example_base.h"
 
+namespace gfx {
+class RenderText;
+}
+
 namespace views {
 
 class Checkbox;
@@ -22,7 +26,7 @@ class VIEWS_EXAMPLES_EXPORT MultilineExample : public ExampleBase,
                                                public TextfieldController,
                                                public ButtonListener {
  public:
-  MultilineExample();
+  explicit MultilineExample(const char* name);
   ~MultilineExample() override;
 
   // ExampleBase:
@@ -31,13 +35,16 @@ class VIEWS_EXAMPLES_EXPORT MultilineExample : public ExampleBase,
   // ButtonListener:
   void ButtonPressed(Button* sender, const ui::Event& event) override;
 
- private:
+ protected:
   class RenderTextView;
 
+  virtual RenderTextView* CreateTextView();
+
   // TextfieldController:
   void ContentsChanged(Textfield* sender,
                        const base::string16& new_contents) override;
 
+ private:
   RenderTextView* render_text_view_;
   Label* label_;
   Textfield* textfield_;
@@ -48,6 +55,27 @@ class VIEWS_EXAMPLES_EXPORT MultilineExample : public ExampleBase,
   DISALLOW_COPY_AND_ASSIGN(MultilineExample);
 };
 
+// A simple View that hosts a RenderText object.
+class MultilineExample::RenderTextView : public View {
+ public:
+  RenderTextView();
+  ~RenderTextView() override;
+
+  void SetText(const base::string16& new_contents);
+  gfx::RenderText* render_text() { return render_text_.get(); }
+
+  // View:
+  void OnPaint(gfx::Canvas* canvas) override;
+  gfx::Size GetPreferredSize() const override;
+  int GetHeightForWidth(int w) const override;
+  void OnBoundsChanged(const gfx::Rect& previous_bounds) override;
+
+ private:
+  std::unique_ptr<gfx::RenderText> render_text_;
+
+  DISALLOW_COPY_AND_ASSIGN(RenderTextView);
+};
+
 }  // namespace examples
 }  // namespace views