Add UMA stats for pen palette

ash/common/system/chromeos/palette/palette_tray.h

 // Copyright 2016 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 ASH_COMMON_SYSTEM_CHROMEOS_PALETTE_PALETTE_BUTTON_TRAY_H_
 #define ASH_COMMON_SYSTEM_CHROMEOS_PALETTE_PALETTE_BUTTON_TRAY_H_
 
 #include <map>
 #include <memory>
 
@@ skipping 39 matching lines @@
 
   // TrayBackgroundView:
   void ClickedOutsideBubble() override;
   base::string16 GetAccessibleNameForTray() override;
   void HideBubbleWithView(const views::TrayBubbleView* bubble_view) override;
   void SetShelfAlignment(ShelfAlignment alignment) override;
   void AnchorUpdated() override;
 
   // PaletteToolManager::Delegate:
   void HidePalette() override;
+  void RecordPaletteMetrics(ash::PaletteTrayOptions option) override;
 
   // Returns true if the shelf should not autohide.
   bool ShouldBlockShelfAutoHide() const;
 
   // Opens up the palette if it is not already open. Returns true if the palette
   // was opened.
   bool ShowPalette();
 
  private:
   // views::TrayBubbleView::Delegate:
@@ skipping 36 matching lines @@
   std::unique_ptr<TrayBubbleWrapper> bubble_;
 
   // Manages the callback OnPaletteEnabledPrefChanged callback registered to
   // the PaletteDelegate instance.
   std::unique_ptr<PaletteDelegate::EnableListenerSubscription>
       palette_enabled_subscription_;
 
   // Weak pointer, will be parented by TrayContainer for its lifetime.
   views::ImageView* icon_;
 
+  // Used to indicate whether the palette is automatically opened by a stylus
+  // eject event.
+  bool is_palette_auto_opened = false;

[jdufault, 2016/09/02 21:54:30]

What about is_bubble_auto_opened_?

[xiaoyinh(OOO Sep 11-29), 2016/09/06 17:40:05]

Done.

+
+  // Number of actions in pen palette.
+  int num_actions_in_palette = 0;

[jdufault, 2016/09/02 21:54:30]

num_actions_in_bubble_?

[xiaoyinh(OOO Sep 11-29), 2016/09/06 17:40:05]

Done.

+
   base::WeakPtrFactory<PaletteTray> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PaletteTray);
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_SYSTEM_CHROMEOS_PALETTE_PALETTE_BUTTON_TRAY_H_