Remove View::GetPageScrollIncrement and View::GetLineScrollIncrement

Both of these methods always returned 0 and are not overridable.

BUG=

Change-Id: I014897e1533442232e6dbfd973186e094077cf87
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1879721
Auto-Submit: Robert Liao <robliao@chromium.org>
Commit-Queue: Scott Violet <sky@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#710010}

ui/views/controls/scroll_view.cc

@@ -663,19 +663,6 @@ void ScrollView::ScrollToPosition(ScrollBar* source, int position) {
 int ScrollView::GetScrollIncrement(ScrollBar* source, bool is_page,
                                    bool is_positive) {
   bool is_horizontal = source->IsHorizontal();
-  int amount = 0;
-  if (contents_) {
-    if (is_page) {
-      amount = contents_->GetPageScrollIncrement(
-          this, is_horizontal, is_positive);
-    } else {
-      amount = contents_->GetLineScrollIncrement(
-          this, is_horizontal, is_positive);
-    }
-    if (amount > 0)
-      return amount;
-  }
-  // No view, or the view didn't return a valid amount.
   if (is_page) {
     return is_horizontal ? contents_viewport_->width() :
                            contents_viewport_->height();

ui/views/view.cc

@@ -1572,16 +1572,6 @@ void View::ScrollViewToVisible() {
   ScrollRectToVisible(GetLocalBounds());
 }
 
-int View::GetPageScrollIncrement(ScrollView* scroll_view,
-                                 bool is_horizontal, bool is_positive) {
-  return 0;
-}
-
-int View::GetLineScrollIncrement(ScrollView* scroll_view,
-                                 bool is_horizontal, bool is_positive) {
-  return 0;
-}
-
 void View::AddObserver(ViewObserver* observer) {
   CHECK(observer);
   observers_.AddObserver(observer);

ui/views/view.h

@@ -1322,32 +1322,6 @@ class VIEWS_EXPORT View : public ui::LayerDelegate,
   // this function calls ScrollRectToVisible(GetLocalBounds()).
   void ScrollViewToVisible();
 
-  // The following methods are used by ScrollView to determine the amount
-  // to scroll relative to the visible bounds of the view. For example, a
-  // return value of 10 indicates the scroll_view should scroll 10 pixels in
-  // the appropriate direction.
-  //
-  // Each method takes the following parameters:
-  //
-  // is_horizontal: if true, scrolling is along the horizontal axis, otherwise
-  //                the vertical axis.
-  // is_positive: if true, scrolling is by a positive amount. Along the
-  //              vertical axis scrolling by a positive amount equates to
-  //              scrolling down.
-  //
-  // The return value should always be positive and gives the number of pixels
-  // to scroll. ScrollView interprets a return value of 0 (or negative)
-  // to scroll by a default amount.
-  //
-  // See VariableRowHeightScrollHelper and FixedRowHeightScrollHelper for
-  // implementations of common cases.
-  int GetPageScrollIncrement(ScrollView* scroll_view,
-                             bool is_horizontal,
-                             bool is_positive);
-  int GetLineScrollIncrement(ScrollView* scroll_view,
-                             bool is_horizontal,
-                             bool is_positive);
-
   void AddObserver(ViewObserver* observer);
   void RemoveObserver(ViewObserver* observer);
   bool HasObserver(const ViewObserver* observer) const;