modify View::ViewHierarchyChanged signature

- move pararms to a new struct, add a new |move_view| which is used when a view is moved from one parent to another
- this allows NativeViewHost to not remove a reparented view from its widget if its previous and new parents belong to the same widget; this saves resources, and stops spurious webkitvisibilitychange events.
- restructured test code and added test

BUG=236826
TEST=all tests still pass.
TBR=jochen (for content/shell/shell_aura.cc, simple change for ViewHierarchyChanged signature)

Review URL: https://chromiumcodereview.appspot.com/14999006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@199671 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 5 insertions, 7 deletions

diff --git a/ash/system/tray/tray_background_view.cc b/ash/system/tray/tray_background_view.cc
index 3f51d62a..1352ecd 100644
--- a/ash/system/tray/tray_background_view.cc
+++ b/ash/system/tray/tray_background_view.cc
@@ -128,10 +128,9 @@ void TrayBackgroundView::TrayContainer::ChildVisibilityChanged(View* child) {
   PreferredSizeChanged();
 }
 
-void TrayBackgroundView::TrayContainer::ViewHierarchyChanged(bool is_add,
-                                                             View* parent,
-                                                             View* child) {
-  if (parent == this)
+void TrayBackgroundView::TrayContainer::ViewHierarchyChanged(
+    const ViewHierarchyChangedDetails& details) {
+  if (details.parent == this)
     PreferredSizeChanged();
 }
 
diff --git a/ash/system/tray/tray_background_view.h b/ash/system/tray/tray_background_view.h
index 15597ba..a5f8597 100644
--- a/ash/system/tray/tray_background_view.h
+++ b/ash/system/tray/tray_background_view.h
@@ -44,9 +44,8 @@ class ASH_EXPORT TrayBackgroundView : public ActionableView,
     // Overridden from views::View.
     virtual void ChildPreferredSizeChanged(views::View* child) OVERRIDE;
     virtual void ChildVisibilityChanged(View* child) OVERRIDE;
-    virtual void ViewHierarchyChanged(bool is_add,
-                                      View* parent,
-                                      View* child) OVERRIDE;
+    virtual void ViewHierarchyChanged(
+        const ViewHierarchyChangedDetails& details) OVERRIDE;
 
    private:
     void UpdateLayout();