Merge java_staging/src into java/src.

chrome/android/java_staging/src/org/chromium/chrome/browser/ntp/NativePageAssassin.java

Index: chrome/android/java_staging/src/org/chromium/chrome/browser/ntp/NativePageAssassin.java
diff --git a/chrome/android/java_staging/src/org/chromium/chrome/browser/ntp/NativePageAssassin.java b/chrome/android/java_staging/src/org/chromium/chrome/browser/ntp/NativePageAssassin.java
deleted file mode 100644
index b5af95d12566732eb0eb494ec16f463ed576e8d6..0000000000000000000000000000000000000000
--- a/chrome/android/java_staging/src/org/chromium/chrome/browser/ntp/NativePageAssassin.java
+++ /dev/null
@@ -1,97 +0,0 @@
-// Copyright 2015 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-package org.chromium.chrome.browser.ntp;
-
-import org.chromium.chrome.browser.FrozenNativePage;
-import org.chromium.chrome.browser.NativePage;
-import org.chromium.chrome.browser.Tab;
-
-import java.lang.ref.WeakReference;
-import java.util.ArrayList;
-
-/**
- * NativePageAssassin tracks recent tabs and freezes each native page when it hasn't been visible
- * for a while. This keeps hidden NativePages from using up precious memory.
- *
- * The NativePageAssassin is a singleton since having full knowledge of the user's hidden tabs --
- * across all local instances of Chrome and all TabModels -- allows the NativePageAssassin to better
- * estimate which hidden tabs the user is likely to return to.
- *
- * Thread safety: this should only be accessed on the UI thread.
- */
-public class NativePageAssassin {
-
-    private static final NativePageAssassin sInstance = new NativePageAssassin();
-
-    /**
-     * The number of hidden tabs to consider "recent". Any non-recent native page will be frozen.
-     */
-    private static final int MAX_RECENT_TABS = 3;
-
-    /**
-     * The most recently hidden tabs, limited to MAX_RECENT_TABS elements, ordered from oldest to
-     * newest. Visible tabs are not included in this list.
-     */
-    private ArrayList<WeakReference<Tab>> mRecentTabs = new ArrayList<WeakReference<Tab>>(
-            MAX_RECENT_TABS + 1);
-
-    private NativePageAssassin() {}
-
-    /**
-     * @return The one and only NativePageAssassin.
-     */
-    public static NativePageAssassin getInstance() {
-        return sInstance;
-    }
-
-    /**
-     * Call this whenever a tab is shown.
-     *
-     * @param tab The tab being shown.
-     */
-    public void tabShown(Tab tab) {
-        // Remove the tab from the list of recently hidden tabs.
-        for (int i = 0; i < mRecentTabs.size(); i++) {
-            Tab t = mRecentTabs.get(i).get();
-            if (t == tab) {
-                mRecentTabs.remove(i);
-            }
-        }
-    }
-
-    /**
-     * Call this whenever a tab is hidden.
-     *
-     * @param tab The tab being hidden.
-     */
-    public void tabHidden(Tab tab) {
-        mRecentTabs.add(new WeakReference<Tab>(tab));
-
-        // If a tab has just passed the threshold from "recent" to "not recent" and it's displaying
-        // a native page, freeze the native page.
-        if (mRecentTabs.size() <= MAX_RECENT_TABS) return;
-        freeze(mRecentTabs.remove(0).get());
-    }
-
-    /**
-     * Freezes all hidden NativePages that aren't already frozen.
-     */
-    public void freezeAllHiddenPages() {
-        for (int i = 0; i < mRecentTabs.size(); i++) {
-            freeze(mRecentTabs.get(i).get());
-        }
-        mRecentTabs.clear();
-    }
-
-    private void freeze(Tab tab) {
-        if (tab == null) return;
-        NativePage pageToFreeze = tab.getNativePage();
-        if (pageToFreeze == null || pageToFreeze instanceof FrozenNativePage
-                || pageToFreeze.getView().getParent() != null) {
-            return;
-        }
-        tab.freezeNativePage();
-    }
-}