Last_n: disable on Svelte devices.

chrome/browser/android/offline_pages/recent_tab_helper_unittest.cc

Index: chrome/browser/android/offline_pages/recent_tab_helper_unittest.cc
diff --git a/chrome/browser/android/offline_pages/recent_tab_helper_unittest.cc b/chrome/browser/android/offline_pages/recent_tab_helper_unittest.cc
index 205db07c36d10722f99bdf85c0024669986fe192..564b48f1e791a703e713424fb646e905fe00bfd4 100644
--- a/chrome/browser/android/offline_pages/recent_tab_helper_unittest.cc
+++ b/chrome/browser/android/offline_pages/recent_tab_helper_unittest.cc
@@ -333,6 +333,30 @@ TEST_F(RecentTabHelperTest, NoTabIdNoCapture) {
   ASSERT_EQ(0U, GetAllPages().size());
 }
 
+// Checks that last_n is disabled if the device is low-end (aka svelte) but that
+// download requests still work.
+TEST_F(RecentTabHelperTest, LastNDisabledOnSvelte) {
+  // Simulates a low end device.
+  recent_tab_helper()->is_low_end_device_ = true;
+
+  // Navigate and finish loading then hide the tab. Nothing should be saved.
+  NavigateAndCommit(kTestPageUrl);
+  recent_tab_helper()->DocumentOnLoadCompletedInMainFrame();
+  FastForwardSnapshotController();
+  recent_tab_helper()->WasHidden();
+  RunUntilIdle();
+  EXPECT_TRUE(model()->is_loaded());
+  EXPECT_EQ(0U, page_added_count());
+  ASSERT_EQ(0U, GetAllPages().size());
+
+  // But the following download request should work normally
+  recent_tab_helper()->ObserveAndDownloadCurrentPage(NewDownloadClientId(),
+                                                     123L);
+  RunUntilIdle();
+  EXPECT_EQ(1U, page_added_count());
+  ASSERT_EQ(1U, GetAllPages().size());
+}
+
 // Triggers two last_n snapshot captures during a single page load. Should end
 // up with one snapshot, the 1st being replaced by the 2nd.
 TEST_F(RecentTabHelperTest, TwoCapturesSamePageLoad) {