Teach sessions code about UserAgentMetadata overrides

(Making it save/restore them along with regular UA overrides).

Bug: 1061917

Change-Id: I97d11d52d522a83a49221e25612a833e311836d1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2118586
Reviewed-by: Scott Violet <[email protected]>
Commit-Queue: Maksim Orlovich <[email protected]>
Cr-Commit-Position: refs/heads/master@{#756825}
diff --git a/chrome/browser/ui/browser_live_tab_context.h b/chrome/browser/ui/browser_live_tab_context.h
index 68322c8..6f02b146 100644
--- a/chrome/browser/ui/browser_live_tab_context.h
+++ b/chrome/browser/ui/browser_live_tab_context.h
@@ -64,7 +64,8 @@
       bool pin,
       bool from_last_session,
       const sessions::PlatformSpecificTabData* storage_namespace,
-      const std::string& user_agent_override) override;
+      const sessions::SerializedUserAgentOverride& user_agent_override)
+      override;
   sessions::LiveTab* ReplaceRestoredTab(
       const std::vector<sessions::SerializedNavigationEntry>& navigations,
       base::Optional<tab_groups::TabGroupId> group,
@@ -72,7 +73,8 @@
       bool from_last_session,
       const std::string& extension_app_id,
       const sessions::PlatformSpecificTabData* tab_platform_data,
-      const std::string& user_agent_override) override;
+      const sessions::SerializedUserAgentOverride& user_agent_override)
+      override;
   void CloseTab() override;
 
   // see Browser::Create