[ LiveTabContext ] Add function to retrieve saved id from tab group

Adds a function which retrieves a tab group's SavedTabGroupID. This functionality should be used when creating historical groups / tabs for tab restoring.

Bug: 330769406, 324275068
Change-Id: I7be678643a48a41d560497e5a33316424a7b8c76
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5393879
Reviewed-by: Gauthier Ambard <[email protected]>
Reviewed-by: Scott Violet <[email protected]>
Commit-Queue: Darryl James <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1278621}
diff --git a/chrome/browser/ui/browser_live_tab_context.h b/chrome/browser/ui/browser_live_tab_context.h
index 73b5567..522c5fc 100644
--- a/chrome/browser/ui/browser_live_tab_context.h
+++ b/chrome/browser/ui/browser_live_tab_context.h
@@ -18,6 +18,10 @@
 class Browser;
 class Profile;
 
+namespace base {
+class Uuid;
+}
+
 namespace content {
 class WebContents;
 }
@@ -54,6 +58,8 @@
       int index) const override;
   const tab_groups::TabGroupVisualData* GetVisualDataForGroup(
       const tab_groups::TabGroupId& group) const override;
+  const std::optional<base::Uuid> GetSavedTabGroupIdForGroup(
+      const tab_groups::TabGroupId& group) const override;
   bool IsTabPinned(int index) const override;
   void SetVisualDataForGroup(
       const tab_groups::TabGroupId& group,