views: Make SubmenuView::PaintChildren use the canvas via PaintRecorder

This uses a PaintRecorder to get at the canvas() for painting, instead
of grabbing it directly off PaintContext. This will allow PaintContext
to be backed by a DisplayItemList instead of a Canvas.

R=sadrul, sky
BUG=466426

Review URL: https://codereview.chromium.org/1064763002

Cr-Commit-Position: refs/heads/master@{#324080}

ui/views/controls/menu/submenu_view.cc

@@ -9,6 +9,7 @@
 #include "base/compiler_specific.h"
 #include "ui/accessibility/ax_view_state.h"
 #include "ui/compositor/paint_context.h"
+#include "ui/compositor/paint_recorder.h"
 #include "ui/events/event.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/geometry/safe_integer_conversions.h"
@@ -191,8 +192,25 @@ ui::TextInputClient* SubmenuView::GetTextInputClient() {
 void SubmenuView::PaintChildren(const ui::PaintContext& context) {
   View::PaintChildren(context);
 
-  if (drop_item_ && drop_position_ != MenuDelegate::DROP_ON)
-    PaintDropIndicator(context.canvas(), drop_item_, drop_position_);
+  bool paint_drop_indicator = false;
+  if (drop_item_) {
+    switch (drop_position_) {
+      case MenuDelegate::DROP_NONE:
+      case MenuDelegate::DROP_ON:
+        break;
+      case MenuDelegate::DROP_UNKNOWN:
+      case MenuDelegate::DROP_BEFORE:
+      case MenuDelegate::DROP_AFTER:
+        paint_drop_indicator = true;
+        break;
+    }
+  }
+
+  if (paint_drop_indicator) {
+    gfx::Rect bounds = CalculateDropIndicatorBounds(drop_item_, drop_position_);
+    ui::PaintRecorder recorder(context);
+    recorder.canvas()->FillRect(bounds, kDropIndicatorColor);
+  }
 }
 
 bool SubmenuView::GetDropFormats(
@@ -445,16 +463,6 @@ void SubmenuView::OnBoundsChanged(const gfx::Rect& previous_bounds) {
   SchedulePaint();
 }
 
-void SubmenuView::PaintDropIndicator(gfx::Canvas* canvas,
-                                     MenuItemView* item,
-                                     MenuDelegate::DropPosition position) {
-  if (position == MenuDelegate::DROP_NONE)
-    return;
-
-  gfx::Rect bounds = CalculateDropIndicatorBounds(item, position);
-  canvas->FillRect(bounds, kDropIndicatorColor);
-}
-
 void SubmenuView::SchedulePaintForDropIndicator(
     MenuItemView* item,
     MenuDelegate::DropPosition position) {

ui/views/controls/menu/submenu_view.h

@@ -166,12 +166,6 @@ class VIEWS_EXPORT SubmenuView : public PrefixDelegate,
   void ChildPreferredSizeChanged(View* child) override;
 
  private:
-  // Paints the drop indicator. This is only invoked if item is non-NULL and
-  // position is not DROP_NONE.
-  void PaintDropIndicator(gfx::Canvas* canvas,
-                          MenuItemView* item,
-                          MenuDelegate::DropPosition position);
-
   void SchedulePaintForDropIndicator(MenuItemView* item,
                                      MenuDelegate::DropPosition position);