Bug 1232651 - don't show search suggestions in private browsing r=mcomella

We also remove the special case for updating mSuggestClient when
search engines are modified during private browsing - this causes
a weird edge case where we potentially show history suggestions
after switching search engines (this seems to be because having
mSuggestClient == null avoids us even reaching the stage where
we usually recycle unneeded suggestions).

--HG--
extra : commitid : 7nSA4lqzGKX
extra : rebase_source : 04ae0ccda497f19152f15dc6592bdb90b6af5864

mobile/android/base/java/org/mozilla/gecko/home/BrowserSearch.java

@@ -253,7 +253,7 @@ public class BrowserSearch extends HomeFragment
     @Override
     public void onHiddenChanged(boolean hidden) {
         if (!hidden) {
-            Tab tab = Tabs.getInstance().getSelectedTab();
+            final Tab tab = Tabs.getInstance().getSelectedTab();
             final boolean isPrivate = (tab != null && tab.isPrivate());
 
             // Removes Search Suggestions Loader if in private browsing mode
@@ -593,7 +593,11 @@ public class BrowserSearch extends HomeFragment
     }
 
     private void filterSuggestions() {
-        if (mSuggestClient == null || (!mSuggestionsEnabled && !mSavedSearchesEnabled)) {
+        Tab tab = Tabs.getInstance().getSelectedTab();
+        final boolean isPrivate = (tab != null && tab.isPrivate());
+
+        if (isPrivate || (!mSuggestionsEnabled && !mSavedSearchesEnabled)) {
+            mSearchHistorySuggestions.clear();
             return;
         }
 
@@ -670,16 +674,7 @@ public class BrowserSearch extends HomeFragment
                     // is also the default engine.
                     searchEngines.add(0, engine);
 
-                    // The only time Tabs.getInstance().getSelectedTab() should
-                    // be null is when we're restoring after a crash. We should
-                    // never restore private tabs when that happens, so it
-                    // should be safe to assume that null means non-private.
-                    Tab tab = Tabs.getInstance().getSelectedTab();
-                    final boolean isPrivate = (tab != null && tab.isPrivate());
-
-                    // Only create a new instance of SuggestClient if it hasn't been
-                    // set yet.
-                    maybeSetSuggestClient(suggestTemplate, isPrivate);
+                    ensureSuggestClientIsSet(suggestTemplate);
                 } else {
                     searchEngines.add(engine);
                 }
@@ -696,12 +691,15 @@ public class BrowserSearch extends HomeFragment
                 mAdapter.notifyDataSetChanged();
             }
 
+            final Tab tab = Tabs.getInstance().getSelectedTab();
+            final boolean isPrivate = (tab != null && tab.isPrivate());
+
             // Show suggestions opt-in prompt only if suggestions are not enabled yet,
             // user hasn't been prompted and we're not on a private browsing tab.
             // The prompt might have been inflated already when this view was previously called.
             // Remove the opt-in prompt if it has been inflated in the view and dealt with by the user,
             // or if we're on a private browsing tab
-            if (!mSuggestionsEnabled && !suggestionsPrompted && mSuggestClient != null) {
+            if (!mSuggestionsEnabled && !suggestionsPrompted && !isPrivate) {
                 showSuggestionsOptIn();
             } else {
                 removeSuggestionsOptIn();
@@ -735,12 +733,7 @@ public class BrowserSearch extends HomeFragment
         mSearchListener.onSearch(searchEngine, mSearchTerm);
     }
 
-    private void maybeSetSuggestClient(final String suggestTemplate, final boolean isPrivate) {
-        if (isPrivate) {
-            mSuggestClient = null;
-            return;
-        }
-
+    private void ensureSuggestClientIsSet(final String suggestTemplate) {
         if (mSuggestClient != null) {
             return;
         }