Add debug option to disable performance features for testing

Change-Id: I508448907a83fb32028cb28eb64b72f97a863fd0
diff --git a/src/com/android/browser/BrowserSettings.java b/src/com/android/browser/BrowserSettings.java
index 9de584d..82402c1 100644
--- a/src/com/android/browser/BrowserSettings.java
+++ b/src/com/android/browser/BrowserSettings.java
@@ -901,6 +901,11 @@
         return mPrefs.getBoolean(PREF_ENABLE_HARDWARE_ACCEL_SKIA, false);
     }
 
+    public boolean isDisablePerfFeatures() {
+        // This value is flipped in the prefs.
+        return !mPrefs.getBoolean(PREF_DISABLE_PERF, true);
+    }
+
     // -----------------------------
     // getter/setters for hidden_debug_preferences.xml
     // -----------------------------