[merge to 124] splitview: Suspected fix for SetWindowsTransformDuring…

…Resizing crash

This clamps the values of `GetClosestFixedDividerPosition()` and
`CalculateDividerPosition()` to be between 0 and the work area length.

Test: compiles
Bug: b/327685487
Change-Id: Ifba1dad1b79208292094844eb2a6ab86941dc637
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5414873
Commit-Queue: Sophie Wen <sophiewen@chromium.org>
Reviewed-by: Ahmed Fakhry <afakhry@chromium.org>
Cr-Original-Commit-Position: refs/heads/main@{#1282845}
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5449870
Cr-Commit-Position: refs/branch-heads/6367@{#798}
Cr-Branched-From: d158c6d-refs/heads/main@{#1274542}

ash/wm/splitview/split_view_controller.cc

@@ -2093,7 +2093,7 @@ int SplitViewController::GetClosestFixedDividerPosition(int divider_position) {
   if (divider_closest_ratio_ > 0.f && divider_closest_ratio_ < 1.f) {
     fixed_position -= kSplitviewDividerShortSideLength / 2;
   }
-  return fixed_position;
+  return std::clamp(fixed_position, 0, divider_upper_limit);
 }
 
 void SplitViewController::StopAndShoveAnimatedDivider() {

ash/wm/splitview/split_view_utils.cc

@@ -764,9 +764,11 @@ int CalculateDividerPosition(aura::Window* root_window,
   // 1-DIP gap between snapped windows precludes multiresizing. See b/262011280.
   const float snap_length = (divider_upper_limit - divider_delta) * snap_ratio;
 
-  return snap_position == SnapPosition::kPrimary
-             ? snap_length
-             : divider_upper_limit - snap_length - divider_delta;
+  return std::clamp(
+      static_cast<int>(snap_position == SnapPosition::kPrimary
+                           ? snap_length
+                           : divider_upper_limit - snap_length - divider_delta),
+      0, divider_upper_limit);
 }
 
 int GetEquivalentDividerPosition(aura::Window* window,

ash/wm/splitview/split_view_utils.h

@@ -221,8 +221,9 @@ int GetDividerPositionUpperLimit(aura::Window* root_window);
 int GetMinimumWindowLength(aura::Window* window, bool horizontal);
 
 // Returns the target divider position for `root_window` for `snap_ratio` at
-// `snap_position`. `account_for_divider_width` will decide whether the divider
-// shorter side width will be subtracted or not.
+// `snap_position`, clamped between 0 and the upper limit of `root_window`.
+// `account_for_divider_width` will decide whether the divider shorter side
+// width will be subtracted or not.
 int CalculateDividerPosition(aura::Window* root_window,
                              SnapPosition snap_position,
                              float snap_ratio,