[ToolbarMVC] Clean up LocationBar destruction and re-creation

Testing a smaller (included) fix for a crash in updateMicButtonState
revealed a few other post-destruction issues that were previously
hidden by LocationBarLayout never being nulled out. So this CL
* Null checks VoiceRecognitionHandler in updateMicButtonState
* Guards against post-destruction callback/delegate invocation in
URLBar
* Prevents a post-destruction call to onSuggestionsReceived in
AutocompleteMediator (and fixes incorrect documentation)

Bug: 1151225, 1151080, 1146585
Change-Id: Iae295a7629c35aeae8ce357e414b05e6847d62e4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2552570Reviewed-by: Filip Gorski <fgorski@chromium.org>
Reviewed-by: Tomasz Wiszkowski <ender@google.com>
Commit-Queue: Patrick Noland <pnoland@chromium.org>
Cr-Commit-Position: refs/heads/master@{#829885}

chrome/android/java/src/org/chromium/chrome/browser/omnibox/LocationBarCoordinator.java

@@ -155,6 +155,7 @@ public final class LocationBarCoordinator
             mSubCoordinator.destroy();
             mSubCoordinator = null;
         }
+        mUrlCoordinator.destroy();
         mUrlCoordinator = null;
         mLocationBarLayout.removeUrlFocusChangeListener(mAutocompleteCoordinator);
         mAutocompleteCoordinator.destroy();

chrome/android/java/src/org/chromium/chrome/browser/omnibox/LocationBarLayout.java

@@ -669,7 +669,8 @@ public class LocationBarLayout extends FrameLayout implements OnClickListener {
      * need to be updated.
      */
     /* package */ void updateMicButtonState() {
-        mVoiceSearchEnabled = mVoiceRecognitionHandler.isVoiceSearchEnabled();
+        mVoiceSearchEnabled =
+                mVoiceRecognitionHandler != null && mVoiceRecognitionHandler.isVoiceSearchEnabled();
         updateButtonVisibility();
     }
 

chrome/android/java/src/org/chromium/chrome/browser/omnibox/UrlBar.java

@@ -222,12 +222,14 @@ public abstract class UrlBar extends AutocompleteEditText {
                 new GestureDetector(getContext(), new GestureDetector.SimpleOnGestureListener() {
                     @Override
                     public void onLongPress(MotionEvent e) {
+                        if (mUrlBarDelegate == null) return;
                         mUrlBarDelegate.gestureDetected(true);
                         performLongClick();
                     }
 
                     @Override
                     public boolean onSingleTapUp(MotionEvent e) {
+                        if (mUrlBarDelegate == null) return true;
                         requestFocus();
                         mUrlBarDelegate.gestureDetected(false);
                         return true;
@@ -244,6 +246,15 @@ public abstract class UrlBar extends AutocompleteEditText {
         ApiCompatibilityUtils.disableSmartSelectionTextClassifier(this);
     }
 
+    public void destroy() {
+        setAllowFocus(false);
+        mUrlBarDelegate = null;
+        setOnFocusChangeListener(null);
+        mTextContextMenuDelegate = null;
+        mUrlTextChangeListener = null;
+        mTextChangedListener = null;
+    }
+
     /**
      * Initialize the delegate that allows interaction with the Window.
      */
@@ -340,7 +351,8 @@ public abstract class UrlBar extends AutocompleteEditText {
 
     @Override
     public View focusSearch(int direction) {
-        if (direction == View.FOCUS_BACKWARD && mUrlBarDelegate.getViewForUrlBackFocus() != null) {
+        if (mUrlBarDelegate != null && direction == View.FOCUS_BACKWARD
+                && mUrlBarDelegate.getViewForUrlBackFocus() != null) {
             return mUrlBarDelegate.getViewForUrlBackFocus();
         } else {
             return super.focusSearch(direction);

chrome/android/java/src/org/chromium/chrome/browser/omnibox/UrlBarCoordinator.java

@@ -37,8 +37,8 @@ public class UrlBarCoordinator implements UrlBarEditingTextStateProvider {
         int SELECT_END = 1;
     }
 
-    private final UrlBar mUrlBar;
-    private final UrlBarMediator mMediator;
+    private UrlBar mUrlBar;
+    private UrlBarMediator mMediator;
 
     /**
      * Constructs a coordinator for the given UrlBar view.
@@ -67,6 +67,13 @@ public class UrlBarCoordinator implements UrlBarEditingTextStateProvider {
         mMediator = new UrlBarMediator(model, focusChangeCallback);
     }
 
+    public void destroy() {
+        mMediator.destroy();
+        mMediator = null;
+        mUrlBar.destroy();
+        mUrlBar = null;
+    }
+
     /** @see UrlBarMediator#addUrlTextChangeListener(UrlTextChangeListener) */
     public void addUrlTextChangeListener(UrlTextChangeListener listener) {
         mMediator.addUrlTextChangeListener(listener);

chrome/android/java/src/org/chromium/chrome/browser/omnibox/UrlBarMediator.java

@@ -79,6 +79,12 @@ class UrlBarMediator
         setUseDarkTextColors(true);
     }
 
+    public void destroy() {
+        mUrlTextChangeListeners.clear();
+        mTextChangedListeners.clear();
+        mOnFocusChangeCallback = (unused) -> {};
+    }
+
     /** Adds a listener for url text changes. */
     public void addUrlTextChangeListener(UrlTextChangeListener listener) {
         mUrlTextChangeListeners.add(listener);

chrome/android/java/src/org/chromium/chrome/browser/omnibox/suggestions/AutocompleteController.java

@@ -198,7 +198,7 @@ public class AutocompleteController {
      * {@link #start(Profile,String, String, boolean)}.
      *
      * <p>
-     * Calling this method with {@code false}, will result in
+     * Calling this method with {@code true}, will result in
      * {@link #onSuggestionsReceived(AutocompleteResult, String, long)} being called with an empty
      * result set.
      *

chrome/android/java/src/org/chromium/chrome/browser/omnibox/suggestions/AutocompleteMediator.java

@@ -223,7 +223,7 @@ class AutocompleteMediator implements OnSuggestionsReceivedListener, StartStopWi
     }
 
     public void destroy() {
-        stopAutocomplete(true);
+        stopAutocomplete(false);
         mDropdownViewInfoListBuilder.destroy();
         if (mTabObserver != null) {
             mTabObserver.destroy();