helium/ui: reduce side panel minimum width

patches/helium/ui/side-panel.patch

@@ -64,3 +64,68 @@
    }
  }
 
+// Reduce minimum acceptable side panel content width without changing the default size.
+--- a/chrome/browser/ui/views/side_panel/side_panel.cc
++++ b/chrome/browser/ui/views/side_panel/side_panel.cc
+@@ -419,8 +419,7 @@ void SidePanel::UpdateWidthOnEntryChange
+   // 1. Use the user's manually resized width
+   // 2. Use the side panels default width
+   // NOTE: If not specified, the side panel will default to
+-  // SidePanelEntry::kSidePanelDefaultContentWidth which evaluates to the same
+-  // value as GetMinimumSize().
++  // SidePanelEntry::kSidePanelDefaultContentWidth
+   if (std::optional<int> width_from_pref = dict.FindInt(panel_id)) {
+     SetPanelWidth(width_from_pref.value());
+   } else {
+@@ -444,6 +443,13 @@ bool SidePanel::IsRightAligned() const {
+ gfx::Size SidePanel::GetMinimumSize() const {
+   const int min_height = 0;
+   return gfx::Size(
++      SidePanelEntry::kSidePanelMinimumContentWidth + GetBorderInsets().width(),
++      min_height);
++}
++
++gfx::Size SidePanel::GetDefaultSize() const {
++  const int min_height = 0;
++  return gfx::Size(
+       SidePanelEntry::kSidePanelDefaultContentWidth + GetBorderInsets().width(),
+       min_height);
+ }
+@@ -614,6 +620,13 @@ void SidePanel::OnResize(int resize_amou
+     proposed_width = minimum_width;
+   }
+
++  // Snap to default_width if the proposed_width is close enough.
++  const int default_width = GetDefaultSize().width();
++  const int snap_diff = 20;
++  if (abs(proposed_width - default_width) < snap_diff) {
++      proposed_width = default_width;
++  }
++
+   if (width() != proposed_width) {
+     if (SidePanelUI* side_panel_ui =
+             browser_view_->browser()->GetFeatures().side_panel_ui()) {
+--- a/chrome/browser/ui/views/side_panel/side_panel_entry.h
++++ b/chrome/browser/ui/views/side_panel/side_panel_entry.h
+@@ -38,8 +38,10 @@ class SidePanelEntry final : public ui::
+     kToolbar,
+   };
+
+-  // The default and minimum acceptable side panel content width.
++  // The default side panel content width.
+   static constexpr int kSidePanelDefaultContentWidth = 360;
++  // The minimum acceptable side panel content width
++  static constexpr int kSidePanelMinimumContentWidth = 260;
+   using CreateContentCallback =
+       base::RepeatingCallback<std::unique_ptr<views::View>(
+           SidePanelEntryScope&)>;
+--- a/chrome/browser/ui/views/side_panel/side_panel.h
++++ b/chrome/browser/ui/views/side_panel/side_panel.h
+@@ -51,6 +51,7 @@ class SidePanel : public views::Accessib
+   HorizontalAlignment GetHorizontalAlignment() const;
+   bool IsRightAligned() const;
+   gfx::Size GetMinimumSize() const override;
++  gfx::Size GetDefaultSize() const;
+   bool IsClosing();
+   void DisableAnimationsForTesting() { animations_disabled_ = true; }
+   void SetKeyboardResized(bool keyboard_resized) {