Revert of Last_n: Delete previously saved snapshot when navigating.

chrome/android/javatests/src/org/chromium/chrome/browser/offlinepages/RecentTabsTest.java

Index: chrome/android/javatests/src/org/chromium/chrome/browser/offlinepages/RecentTabsTest.java
diff --git a/chrome/android/javatests/src/org/chromium/chrome/browser/offlinepages/RecentTabsTest.java b/chrome/android/javatests/src/org/chromium/chrome/browser/offlinepages/RecentTabsTest.java
index 5c55ae4320848c438ed2a7384ff14118ef182ea5..4560a32e6fb2501af6a4df92f66329449d9bac62 100644
--- a/chrome/android/javatests/src/org/chromium/chrome/browser/offlinepages/RecentTabsTest.java
+++ b/chrome/android/javatests/src/org/chromium/chrome/browser/offlinepages/RecentTabsTest.java
@@ -5,7 +5,6 @@
 package org.chromium.chrome.browser.offlinepages;
 
 import android.content.Context;
-import android.support.annotation.MainThread;
 import android.support.test.filters.MediumTest;
 
 import org.chromium.base.Callback;
@@ -31,13 +30,11 @@
 @CommandLineFlags.Add("enable-features=OfflineRecentPages")
 public class RecentTabsTest extends ChromeTabbedActivityTestBase {
     private static final String TEST_PAGE = "/chrome/test/data/android/about.html";
-    private static final String TEST_PAGE_2 = "/chrome/test/data/android/simple.html";
     private static final int TIMEOUT_MS = 5000;
 
     private OfflinePageBridge mOfflinePageBridge;
     private EmbeddedTestServer mTestServer;
     private String mTestPage;
-    private String mTestPage2;
 
     private void initializeBridgeForProfile(final boolean incognitoProfile)
             throws InterruptedException {
@@ -87,7 +84,6 @@
 
         mTestServer = EmbeddedTestServer.createAndStartServer(getInstrumentation().getContext());
         mTestPage = mTestServer.getURL(TEST_PAGE);
-        mTestPage2 = mTestServer.getURL(TEST_PAGE_2);
     }
 
     @Override
@@ -113,9 +109,9 @@
         // The tab should be foreground and so no snapshot should exist.
         assertNull(getPageByClientId(firstTabClientId));
 
-        // Note: switching to a new tab must occur after the SnapshotController believes the page
-        // quality is good enough.  With the debug flag, the delay after DomContentLoaded is 0 so we
-        // can definitely snapshot after onload (which is what |loadUrlInNewTab| waits for).
+        // Note, that switching to a new tab must occur after the SnapshotController believes the
+        // page quality is good enough.  With the debug flag, the delay after DomContentLoaded is 0
+        // so we can definitely snapshot after onload (which is what |loadUrlInNewTab| waits for).
 
         // Switch to a new tab to cause the WebContents hidden event.
         loadUrlInNewTab("about:blank");
@@ -124,10 +120,10 @@
     }
 
     /**
-     * Note: this test relies on a sleeping period because some of the monitored actions are
-     * difficult to track deterministically. A sleep time of 100 ms was chosen based on local
-     * testing and is expected to be "safe". Nevertheless if flakiness is detected it might have to
-     * be further increased.
+     * Note: this test relies on a sleeping period because some of the taking actions are
+     * complicated to track otherwise, so there is the possibility of flakiness. I chose 100ms from
+     * local testing and I expect it to be "safe" but it flakiness is detected it might have to be
+     * further increased.
      */
     @CommandLineFlags.Add("short-offline-page-snapshot-delay-for-test")
     @MediumTest
@@ -180,83 +176,6 @@
         assertEquals(tabModelSelector.getCurrentTab(), newTab);
         assertTrue(tab.isHidden());
         waitForPageWithClientId(firstTabClientId);
-    }
-
-    /**
-     * Verifies that a snapshot created by last_n is properly deleted when the tab is navigated to
-     * another page. The deletion of snapshots for pages that should not be available anymore is a
-     * privacy requirement for last_n.
-     */
-    @CommandLineFlags.Add("short-offline-page-snapshot-delay-for-test")
-    @MediumTest
-    public void testLastNPageIsDeletedUponNavigation() throws Exception {
-        // The tab of interest.
-        final Tab tab = loadUrlInNewTab(mTestPage);
-        final TabModelSelector tabModelSelector = tab.getTabModelSelector();
-
-        final ClientId firstTabClientId =
-                new ClientId(OfflinePageBridge.LAST_N_NAMESPACE, Integer.toString(tab.getId()));
-
-        // Switch to a new tab and wait for the snapshot to be created.
-        loadUrlInNewTab("about:blank");
-        waitForPageWithClientId(firstTabClientId);
-        OfflinePageItem offlinePage = getPageByClientId(firstTabClientId);
-        assertFalse(tab.equals(tabModelSelector.getCurrentTab()));
-
-        // Switch back to the initial tab and install the page deletion monitor for later usage.
-        final OfflinePageDeletionMonitor deletionMonitor =
-                new OfflinePageDeletionMonitor(offlinePage.getOfflineId());
-        ThreadUtils.runOnUiThreadBlocking(new Runnable() {
-            @Override
-            public void run() {
-                TabModel tabModel = tabModelSelector.getModelForTabId(tab.getId());
-                int tabIndex = TabModelUtils.getTabIndexById(tabModel, tab.getId());
-                TabModelUtils.setIndex(tabModel, tabIndex);
-                deletionMonitor.installObserver();
-            }
-        });
-        assertEquals(tabModelSelector.getCurrentTab(), tab);
-
-        // Navigate to a new page and confirm the previously created snapshot has been deleted.
-        loadUrl(mTestPage2);
-        deletionMonitor.assertDeleted();
-    }
-
-    /**
-     * Verifies that a snapshot created by last_n is properly deleted when the tab is closed. The
-     * deletion of snapshots for pages that should not be available anymore is a privacy requirement
-     * for last_n.
-     */
-    @CommandLineFlags.Add("short-offline-page-snapshot-delay-for-test")
-    @MediumTest
-    public void testLastNPageIsDeletedUponClosure() throws Exception {
-        // The tab of interest.
-        final Tab tab = loadUrlInNewTab(mTestPage);
-        final TabModelSelector tabModelSelector = tab.getTabModelSelector();
-
-        final ClientId firstTabClientId =
-                new ClientId(OfflinePageBridge.LAST_N_NAMESPACE, Integer.toString(tab.getId()));
-
-        // Switch to a new tab and wait for the snapshot to be created.
-        loadUrlInNewTab("about:blank");
-        waitForPageWithClientId(firstTabClientId);
-        OfflinePageItem offlinePage = getPageByClientId(firstTabClientId);
-
-        // Requests closing of the tab allowing for closure undo and checks it's actually closing.
-        final int tabId = tab.getId();
-        final OfflinePageDeletionMonitor deletionMonitor =
-                new OfflinePageDeletionMonitor(offlinePage.getOfflineId());
-        ThreadUtils.runOnUiThreadBlocking(new Runnable() {
-            @Override
-            public void run() {
-                deletionMonitor.installObserver();
-                TabModel tabModel = tabModelSelector.getModelForTabId(tabId);
-                tabModel.closeTab(tab, false, false, true);
-                tabModel.commitTabClosure(tabId);
-            }
-        });
-        assertNull(tabModelSelector.getTabById(tabId));
-        deletionMonitor.assertDeleted();
     }
 
     private void waitForPageWithClientId(final ClientId clientId) throws InterruptedException {
@@ -278,32 +197,6 @@
             }
         });
         assertTrue(semaphore.tryAcquire(TIMEOUT_MS, TimeUnit.MILLISECONDS));
-    }
-
-    private class OfflinePageDeletionMonitor {
-        private final Semaphore mSemaphore = new Semaphore(0);
-        private final long mOfflineId;
-
-        public OfflinePageDeletionMonitor(long offlineId) {
-            mOfflineId = offlineId;
-        }
-
-        @MainThread
-        public void installObserver() {
-            mOfflinePageBridge.addObserver(new OfflinePageModelObserver() {
-                @Override
-                public void offlinePageDeleted(long offlineId, ClientId clientId) {
-                    if (offlineId == mOfflineId) {
-                        mOfflinePageBridge.removeObserver(this);
-                        mSemaphore.release();
-                    }
-                }
-            });
-        }
-
-        public void assertDeleted() throws InterruptedException {
-            assertTrue(mSemaphore.tryAcquire(TIMEOUT_MS, TimeUnit.MILLISECONDS));
-        }
     }
 
     private OfflinePageItem getPageByClientId(ClientId clientId) throws InterruptedException {
@@ -330,24 +223,4 @@
         assertTrue(semaphore.tryAcquire(TIMEOUT_MS, TimeUnit.MILLISECONDS));
         return result[0];
     }
-
-    private OfflinePageItem getPageByOfflineId(final long offlineId) throws InterruptedException {
-        final OfflinePageItem[] result = {null};
-        final Semaphore semaphore = new Semaphore(0);
-
-        ThreadUtils.runOnUiThread(new Runnable() {
-            @Override
-            public void run() {
-                mOfflinePageBridge.getPageByOfflineId(offlineId, new Callback<OfflinePageItem>() {
-                    @Override
-                    public void onResult(OfflinePageItem item) {
-                        result[0] = item;
-                        semaphore.release();
-                    }
-                });
-            }
-        });
-        assertTrue(semaphore.tryAcquire(TIMEOUT_MS, TimeUnit.MILLISECONDS));
-        return result[0];
-    }
 }