[ios] Update horizontal insets for both ipad and iphone

Updates to the insets in response to rotations are necessary for iphones
with notches so that they match the new intrinsic safe area insets.

Bug: 1151932
Change-Id: I2405550da8e9d75899d422ea58a63d54b6780b2e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2568543
Commit-Queue: Chris Lu <thegreenfrog@chromium.org>
Auto-Submit: Chris Lu <thegreenfrog@chromium.org>
Reviewed-by: Rohit Rao <rohitrao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#836352}

ios/chrome/browser/ui/browser_view/browser_view_controller.mm

@@ -1690,9 +1690,8 @@ NSString* const kBrowserViewControllerSnackbarCategory =
       }
       completion:^(id<UIViewControllerTransitionCoordinatorContext> context) {
         BrowserViewController* strongSelf = weakSelf;
-        // Resize horizontal viewport if Smooth Scrolling is on for multiwindow.
-        if (fullscreen::features::ShouldUseSmoothScrolling() &&
-            ui::GetDeviceFormFactor() == ui::DEVICE_FORM_FACTOR_TABLET) {
+        // Resize horizontal viewport if Smooth Scrolling is on.
+        if (fullscreen::features::ShouldUseSmoothScrolling()) {
           strongSelf.fullscreenController->ResizeHorizontalViewport();
         }
         if (!base::FeatureList::IsEnabled(kModernTabStrip)) {
@@ -2453,9 +2452,8 @@ NSString* const kBrowserViewControllerSnackbarCategory =
       self.browserContainerViewController.contentView =
           [self viewForWebState:webState];
     }
-    // Resize horizontal viewport if Smooth Scrolling is on for multiwindow.
-    if (fullscreen::features::ShouldUseSmoothScrolling() &&
-        ui::GetDeviceFormFactor() == ui::DEVICE_FORM_FACTOR_TABLET) {
+    // Resize horizontal viewport if Smooth Scrolling is on.
+    if (fullscreen::features::ShouldUseSmoothScrolling()) {
       self.fullscreenController->ResizeHorizontalViewport();
     }
   }