Disable SearchSuggestions in incognito mode

 Bug: 3336558

Change-Id: Ie88eddee0f4931a206ba45cec708cdbb69cce008
diff --git a/src/com/android/browser/SuggestionsAdapter.java b/src/com/android/browser/SuggestionsAdapter.java
index c2e203a..3c1a689 100644
--- a/src/com/android/browser/SuggestionsAdapter.java
+++ b/src/com/android/browser/SuggestionsAdapter.java
@@ -70,6 +70,7 @@
     Object mResultsLock = new Object();
     List<String> mVoiceResults;
     boolean mReverseResults;
+    boolean mIncognitoMode;
 
     interface CompletionListener {
 
@@ -279,7 +280,9 @@
         }
 
         void startSuggestionsAsync(final CharSequence constraint) {
-            new SlowFilterTask().execute(constraint);
+            if (!mIncognitoMode) {
+                new SlowFilterTask().execute(constraint);
+            }
         }
 
         @Override
@@ -564,4 +567,8 @@
         mSuggestResults = null;
     }
 
+    public void setIncognitoMode(boolean incognito) {
+        mIncognitoMode = incognito;
+        clearCache();
+    }
 }