Remove mActivity from Tab and look at windowAndroid for tab

chrome/android/java/src/org/chromium/chrome/browser/download/ChromeDownloadDelegate.java

Index: chrome/android/java/src/org/chromium/chrome/browser/download/ChromeDownloadDelegate.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/download/ChromeDownloadDelegate.java b/chrome/android/java/src/org/chromium/chrome/browser/download/ChromeDownloadDelegate.java
index 52e05fa65d0671bd671359fdf02fe9d975f0daa3..e9c46d95ba99ae779be8c8e4c8ba6f0b0a99515d 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/download/ChromeDownloadDelegate.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/download/ChromeDownloadDelegate.java
@@ -51,8 +51,6 @@ public class ChromeDownloadDelegate
     // The application context.
     private final Context mContext;
     private final Tab mTab;
-    private final TabModelSelector mTabModelSelector;
-
     // Pending download request for a dangerous file.
     private DownloadInfo mPendingRequest;
 
@@ -122,14 +120,11 @@ public class ChromeDownloadDelegate
     /**
      * Creates ChromeDownloadDelegate.
      * @param context The application context.
-     * @param tabModelSelector The TabModelSelector responsible for {@code mTab}.
      * @param tab The corresponding tab instance.
      */
-    public ChromeDownloadDelegate(
-            Context context, TabModelSelector tabModelSelector, Tab tab) {
+    public ChromeDownloadDelegate(Context context, Tab tab) {
         mContext = context;
         mTab = tab;
-        mTabModelSelector = tabModelSelector;
         mPendingRequest = null;
     }
 
@@ -538,7 +533,7 @@ public class ChromeDownloadDelegate
                 || contents.getNavigationController().isInitialNavigation();
         if (isInitialNavigation) {
             // Tab is created just for download, close it.
-            return mTabModelSelector.closeTab(mTab);
+            return mTab.closeTab();
         }
         return false;
     }