Don't override pending shadow_bounds on frame_type change

BUG=b:138996293

Test: `test_that my_crbook cheets_AppPositionTest_P`
Change-Id: If908ba85e4b3b8016341829c2c337b235b954cb0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1792516Reviewed-by: Mitsuru Oshima (Slow) <oshima@chromium.org>
Reviewed-by: Sara Kato <sarakato@chromium.org>
Commit-Queue: Sara Kato <sarakato@chromium.org>
Cr-Commit-Position: refs/heads/master@{#699675}

components/exo/shell_surface_base.cc

@@ -556,6 +556,7 @@ void ShellSurfaceBase::OnSetFrame(SurfaceFrameType frame_type) {
   }
 
   bool frame_was_disabled = !frame_enabled();
+  // TODO(b/141151475): Make frame_type a committable property.
   frame_type_ = frame_type;
   switch (frame_type) {
     case SurfaceFrameType::NONE:
@@ -565,8 +566,10 @@ void ShellSurfaceBase::OnSetFrame(SurfaceFrameType frame_type) {
     case SurfaceFrameType::AUTOHIDE:
     case SurfaceFrameType::OVERLAY:
       // Initialize the shadow if it didn't exist. Do not reset if
-      // the frame type just switched from another enabled type.
-      if (!shadow_bounds_ || frame_was_disabled)
+      // the frame type just switched from another enabled type or
+      // there is a pending shadow_bounds_ change to avoid overriding
+      // a shadow bounds which have been changed and not yet committed.
+      if (!shadow_bounds_ || (frame_was_disabled && !shadow_bounds_changed_))
         shadow_bounds_ = gfx::Rect();
       break;
     case SurfaceFrameType::SHADOW: