Remove CustomTab and have all CustomTabActivity using Tab

chrome/android/java/src/org/chromium/chrome/browser/document/DocumentTab.java

Index: chrome/android/java/src/org/chromium/chrome/browser/document/DocumentTab.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/document/DocumentTab.java b/chrome/android/java/src/org/chromium/chrome/browser/document/DocumentTab.java
index 3fecb55a5f0bc4c48f4f9ad827c3585c8da5298f..ce0b9e5d616073dd243d46db876a358b5d785e82 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/document/DocumentTab.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/document/DocumentTab.java
@@ -17,6 +17,7 @@ import org.chromium.chrome.browser.WebContentsFactory;
 import org.chromium.chrome.browser.compositor.layouts.content.TabContentManager;
 import org.chromium.chrome.browser.tab.EmptyTabObserver;
 import org.chromium.chrome.browser.tab.Tab;
+import org.chromium.chrome.browser.tab.TabDelegateFactory;
 import org.chromium.chrome.browser.tab.TabObserver;
 import org.chromium.chrome.browser.tab.TabUma;
 import org.chromium.chrome.browser.tab.TabUma.TabCreationState;
@@ -121,7 +122,13 @@ public class DocumentTab extends Tab {
                     ? WarmupManager.getInstance().takePrerenderedWebContents()
                     : WebContentsFactory.createWebContents(isIncognito(), initiallyHidden);
         }
-        initialize(webContents, tabContentManager, initiallyHidden);
+        initialize(webContents, tabContentManager, new TabDelegateFactory() {
+            @Override
+            public TabWebContentsDelegateAndroid createWebContentsDelegate(
+                    Tab tab, ChromeActivity activity) {
+                return new DocumentTabWebContentsDelegateAndroid(DocumentTab.this, mActivity);
+            }
+        }, initiallyHidden);
         if (unfreeze) mDidRestoreState = unfreezeContents();
 
         getView().requestFocus();
@@ -158,11 +165,6 @@ public class DocumentTab extends Tab {
         }
     }
 
-    @Override
-    protected TabWebContentsDelegateAndroid createWebContentsDelegate() {
-        return new DocumentTabWebContentsDelegateAndroid(this, mActivity);
-    }
-
     /**
      * @return Whether or not the tab's state was restored.
      */