Fix unnecessary bitmap captures on Tablet UI

Tablets use a different UI design that doesn't use
captures as often as the Phone UI does.
Added checks to ensure captures weren't taking place
unnecessarily.

Change-Id: I54a32e0bd8f1aabd25d5e3bfd19f1604f0d0c082
diff --git a/src/com/android/browser/Controller.java b/src/com/android/browser/Controller.java
index 85a0296..946e456 100644
--- a/src/com/android/browser/Controller.java
+++ b/src/com/android/browser/Controller.java
@@ -2966,7 +2966,8 @@
             if (currentTab != null) {
                 change_tabs = setActive;
                 setActive = false;
-                currentTab.capture();
+                if (mUi instanceof PhoneUi)
+                    currentTab.capture();
             }
         }