Last_n: do not save snapshot of custom tabs.

chrome/browser/android/offline_pages/recent_tab_helper.cc

Index: chrome/browser/android/offline_pages/recent_tab_helper.cc
diff --git a/chrome/browser/android/offline_pages/recent_tab_helper.cc b/chrome/browser/android/offline_pages/recent_tab_helper.cc
index c7aab9f6145608af525dcc97792876fbeda9746a..7f6a91f66431e7e4a08c6d93b2c5b6cecde324db 100644
--- a/chrome/browser/android/offline_pages/recent_tab_helper.cc
+++ b/chrome/browser/android/offline_pages/recent_tab_helper.cc
@@ -49,6 +49,10 @@ class DefaultDelegate: public offline_pages::RecentTabHelper::Delegate {
   }
   bool IsLowEndDevice() override { return is_low_end_device_; }
 
+  bool IsCustomTab(content::WebContents* web_contents) override {
+    return offline_pages::OfflinePageUtils::IsCurrentlyACustomTab(web_contents);
+  }
+
  private:
   // Cached value of whether low end device.
   bool is_low_end_device_;
@@ -266,13 +270,17 @@ void RecentTabHelper::WasHidden() {
   if (!IsOffliningRecentPagesEnabled())
     return;
 
-  // Return immediately if last_n is not listening to tab hidden events, if a
-  // last_n snapshot is currently being saved or if the tab is closing.
+  // Do not save a snapshots if any of these are true:
+  // - Last_n is not listening to tab hidden events.
+  // - A last_n snapshot is currently being saved.
+  // - The tab is in the process of being closed.
+  // - The tab is currently presented as a custom tab.
   if (!last_n_listen_to_tab_hidden_ || last_n_ongoing_snapshot_info_ ||
-      tab_is_closing_) {
+      tab_is_closing_ || delegate_->IsCustomTab(web_contents())) {
     DVLOG(1) << "Will not snapshot for last_n (reasons: "
              << !last_n_listen_to_tab_hidden_ << ", "
              << !!last_n_ongoing_snapshot_info_ << ", " << tab_is_closing_
+             << ", " << delegate_->IsCustomTab(web_contents())
              << ") for: " << web_contents()->GetLastCommittedURL().spec();
     return;
   }