Add User Actions and adding more details to UMA metrics for overscroll navigation

content/browser/web_contents/aura/overscroll_window_animation.h

 // Copyright 2015 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 CONTENT_BROWSER_WEB_CONTENTS_AURA_OVERSCROLL_WINDOW_ANIMATION_H_
 #define CONTENT_BROWSER_WEB_CONTENTS_AURA_OVERSCROLL_WINDOW_ANIMATION_H_
 
 #include <memory>
 
 #include "base/macros.h"
@@ skipping 59 matching lines @@
     virtual void OnOverscrollCancelled() = 0;
   };
 
   explicit OverscrollWindowAnimation(Delegate* delegate);
 
   ~OverscrollWindowAnimation() override;
 
   // Returns true if we are currently animating.
   bool is_active() const { return !!slide_window_; }
 
+  OverscrollSource overscroll_source() { return overscroll_source_; }
+
+  void SetOverscrollSourceForTesting(OverscrollSource source) {
+    overscroll_source_ = source;
+  }
+
   // OverscrollControllerDelegate:
   gfx::Rect GetVisibleBounds() const override;
   bool OnOverscrollUpdate(float delta_x, float delta_y) override;
   void OnOverscrollComplete(OverscrollMode overscroll_mode) override;
   void OnOverscrollModeChange(OverscrollMode old_mode,
-                              OverscrollMode new_mode) override;
+                              OverscrollMode new_mode,
+                              OverscrollSource source) override;
 
  private:
   // Cancels the slide, animating the front and back window to their original
   // positions.
   void CancelSlide();
 
   // Returns a translation on the x axis for the given overscroll.
   float GetTranslationForOverscroll(float delta_x);
 
   // Animates a translation of the given |layer|. If |listen_for_completion| is
@@ skipping 16 matching lines @@
   // Shadow shown under the animated layer.
   std::unique_ptr<ShadowLayerDelegate> shadow_;
 
   // Delegate that provides the animation target and is notified of the
   // animation state.
   Delegate* delegate_;
 
   // The current animation direction.
   Direction direction_;
 
+  // OverscrollSource of the current overscroll gesture. Updated when the new
+  // overscroll gesture starts, before CreateFront/BackWindow callback is called
+  // on the delegate.
+  OverscrollSource overscroll_source_ = OverscrollSource::NONE;
+
   // Indicates if the current slide has been cancelled. True while the cancel
   // animation is in progress.
   bool overscroll_cancelled_;
 
   DISALLOW_COPY_AND_ASSIGN(OverscrollWindowAnimation);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_WEB_CONTENTS_AURA_OVERSCROLL_WINDOW_ANIMATION_H_