Fix the bug that FIP box is misaligned on relaunching in slide over mode.

If the device's size class has changed from RegularXRegular to another or
reversely, the find bar should switch between regular mode and compact mode
accordingly. Hide and then reshow the findbar in BVC.traitCollectionDidChange
if the size class changed.

Bug: 883672
Cq-Include-Trybots: luci.chromium.try:ios-simulator-cronet;luci.chromium.try:ios-simulator-full-configs
Change-Id: I38872c3fd0911e0e99ffae87f51f90c0cf9082fb
Reviewed-on: https://chromium-review.googlesource.com/1256690
Commit-Queue: Yi Su <mrsuyi@chromium.org>
Reviewed-by: Mark Cogan <marq@chromium.org>
Cr-Commit-Position: refs/heads/master@{#595819}

ios/chrome/browser/ui/browser_view_controller.mm

@@ -1836,6 +1836,15 @@ applicationCommandEndpoint:(id<ApplicationCommands>)applicationCommandEndpoint {
     self.currentWebState->GetWebViewProxy().contentInset = contentPadding;
   }
 
+  // If the device's size class has changed from RegularXRegular to another and
+  // vice-versa, the find bar should switch between regular mode and compact
+  // mode accordingly. Hide the findbar here and it will be reshown in [self
+  // updateToobar];
+  if (ShouldShowCompactToolbar(previousTraitCollection) !=
+      ShouldShowCompactToolbar()) {
+    [self hideFindBarWithAnimation:NO];
+  }
+
   // Update the toolbar visibility.
   [self updateToolbar];
 

ios/chrome/browser/ui/uikit_ui_util.h

@@ -205,16 +205,20 @@ bool IsCompactHeight();
 // Whether the |environment| has a compact vertical size class.
 bool IsCompactHeight(id<UITraitEnvironment> environment);
 
-// Whether the the main application window's rootViewController has a regular
-// vertical and regular horizontal size class.
-bool IsRegularXRegularSizeClass();
-
 // Whether toolbar should be shown in compact mode.
 bool ShouldShowCompactToolbar();
+// Whether toolbar should be shown in compact mode in |traitCollection|.
+bool ShouldShowCompactToolbar(UITraitCollection* traitCollection);
 
+// Whether the the main application window's rootViewController has a regular
+// vertical and regular horizontal size class.
+bool IsRegularXRegularSizeClass();
 // Whether the |environment| has a regular vertical and regular horizontal
-// size class. the main application window's rootViewController
+// size class.
 bool IsRegularXRegularSizeClass(id<UITraitEnvironment> environment);
+// Whether the |traitCollection| has a regular vertical and regular horizontal
+// size class.
+bool IsRegularXRegularSizeClass(UITraitCollection* traitCollection);
 
 // Returns whether the toolbar is split between top and bottom toolbar or if it
 // is displayed as only one toolbar.

ios/chrome/browser/ui/uikit_ui_util.mm

@@ -560,16 +560,20 @@ bool IsRegularXRegularSizeClass() {
 }
 
 bool IsRegularXRegularSizeClass(id<UITraitEnvironment> environment) {
-  UITraitCollection* traitCollection = environment.traitCollection;
+  return IsRegularXRegularSizeClass(environment.traitCollection);
+}
+
+bool IsRegularXRegularSizeClass(UITraitCollection* traitCollection) {
   return traitCollection.verticalSizeClass == UIUserInterfaceSizeClassRegular &&
          traitCollection.horizontalSizeClass == UIUserInterfaceSizeClassRegular;
 }
 
+bool ShouldShowCompactToolbar(UITraitCollection* traitCollection) {
+  return !IsRegularXRegularSizeClass(traitCollection);
+}
+
 bool ShouldShowCompactToolbar() {
-  if (IsUIRefreshPhase1Enabled()) {
-    return !IsRegularXRegularSizeClass();
-  }
-  return !IsIPadIdiom();
+  return !IsRegularXRegularSizeClass();
 }
 
 bool IsSplitToolbarMode() {
@@ -577,8 +581,7 @@ bool IsSplitToolbarMode() {
 }
 
 bool IsSplitToolbarMode(id<UITraitEnvironment> environment) {
-  return IsUIRefreshPhase1Enabled() && IsCompactWidth(environment) &&
-         !IsCompactHeight(environment);
+  return IsCompactWidth(environment) && !IsCompactHeight(environment);
 }
 
 // Returns the first responder in the subviews of |view|, or nil if no view in