[Profile menu] Fix long name overflowing the layout

This CL sets the right flex specifications so that the heading label
does not overflow the size of its parent.

Before: https://screenshot.googleplex.com/XowRbDCxFuxxnwZ
After: https://screenshot.googleplex.com/7KL7g5SN3dX2ZEy

Bug: 1166687
Change-Id: I072a651e838ed46df0cc4584638930911224de7b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2628957Reviewed-by: Alex Ilin <alexilin@chromium.org>
Commit-Queue: Jan Krcal <jkrcal@chromium.org>
Auto-Submit: Jan Krcal <jkrcal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#843630}

chrome/browser/ui/views/profiles/profile_menu_view_base.cc

@@ -415,7 +415,7 @@ void BuildProfileBackgroundContainer(
           std::make_unique<views::View>());
   heading_and_image_container->SetProperty(
       views::kFlexBehaviorKey,
-      views::FlexSpecification(views::MinimumFlexSizeRule::kPreferred,
+      views::FlexSpecification(views::MinimumFlexSizeRule::kScaleToZero,
                                views::MaximumFlexSizeRule::kUnbounded)
           .WithOrder(1));
   heading_and_image_container
@@ -628,6 +628,10 @@ void ProfileMenuViewBase::SetProfileIdentityInfo(
     heading_label = std::make_unique<views::Label>(profile_name, font);
     heading_label->SetElideBehavior(gfx::ELIDE_TAIL);
     heading_label->SetHorizontalAlignment(gfx::ALIGN_CENTER);
+    heading_label->SetProperty(
+        views::kFlexBehaviorKey,
+        views::FlexSpecification(views::MinimumFlexSizeRule::kScaleToZero,
+                                 views::MaximumFlexSizeRule::kUnbounded));
     if (background_color) {
       heading_label->SetAutoColorReadabilityEnabled(false);
       heading_label->SetEnabledColor(