Show subject in conversation view in portrait mode.

Change-Id: Ib1918510949ea9498ca68a0718ffb96dc07648b7
diff --git a/src/com/android/mail/ui/ActionBarView.java b/src/com/android/mail/ui/ActionBarView.java
index 8a6bc6f..623a2c7 100644
--- a/src/com/android/mail/ui/ActionBarView.java
+++ b/src/com/android/mail/ui/ActionBarView.java
@@ -100,6 +100,7 @@
      * method talks about why this is required.
      */
     private boolean mIgnoreFirstNavigation = true;
+    private Boolean mShowConversationSubject;
 
     public ActionBarView(Context context) {
         this(context, null);
@@ -396,7 +397,8 @@
                 mActionBar.setDisplayHomeAsUpEnabled(true);
                 // FIXME: use a resource to have fine-grained control over whether the spinner
                 // or the subject appears
-                if (Utils.useTabletUI(mActivity.getActivityContext())) {
+                if (Utils.useTabletUI(mActivity.getActivityContext())
+                        && !showConversationSubject()) {
                     showNavList();
                 } else {
                     setStandardMode();
@@ -430,6 +432,14 @@
         return false;
     }
 
+    private boolean showConversationSubject() {
+        if (mShowConversationSubject == null) {
+            mShowConversationSubject = new Boolean(mActivity.getActivityContext().getResources()
+                    .getBoolean(R.bool.show_conversation_subject));
+        }
+        return mShowConversationSubject;
+    }
+
     /**
      * Put the ActionBar in List navigation mode. This starts the spinner up if it is missing.
      */