Check for null in LocationBarCoordinator.getVoiceRecognitionHandler()

Prevent NullPointerException after destroy() was called.

Bug: 1140333
Fixed: 1139100
Change-Id: I3a8cd6117bf9a01e8c43d98d44798db59da9f0b2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2481289
Commit-Queue: Theresa  <twellington@chromium.org>
Reviewed-by: Theresa  <twellington@chromium.org>
Reviewed-by: Brandon Wylie <wylieb@chromium.org>
Auto-Submit: who/bttk <bttk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#819110}

chrome/android/java/src/org/chromium/chrome/browser/customtabs/features/toolbar/CustomTabToolbar.java

@@ -872,6 +872,7 @@ public class CustomTabToolbar extends ToolbarLayout implements View.OnLongClickL
             return false;
         }
 
+        @Nullable
         @Override
         public VoiceRecognitionHandler getVoiceRecognitionHandler() {
             return null;

chrome/android/java/src/org/chromium/chrome/browser/ntp/FakeboxDelegate.java

@@ -47,10 +47,8 @@ public interface FakeboxDelegate {
      */
     boolean isCurrentPage(NativePage nativePage);
 
-    /**
-     * Get the {@link VoiceRecognitionHandler}.
-     * @return the {@link VoiceRecognitionHandler}
-     */
+    /** Gets the {@link VoiceRecognitionHandler}. */
+    @Nullable
     VoiceRecognitionHandler getVoiceRecognitionHandler();
 
     /**

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

@@ -25,7 +25,7 @@ public interface LocationBar extends UrlBarDelegate, FakeboxDelegate, Destroyabl
     void onNativeLibraryReady();
 
     /** Triggered when the current tab has changed to a {@link NewTabPage}. */
-    default void onTabLoadingNTP(NewTabPage ntp){};
+    default void onTabLoadingNTP(NewTabPage ntp) {}
 
     /**
      * Call to force the UI to update the state of various buttons based on whether or not the

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

@@ -240,8 +240,13 @@ public final class LocationBarCoordinator implements LocationBar {
         return mLocationBarLayout.isCurrentPage(nativePage);
     }
 
+    @Nullable
     @Override
     public VoiceRecognitionHandler getVoiceRecognitionHandler() {
+        // TODO(crbug.com/1140333): StartSurfaceMediator can call this method after destroy().
+        if (mLocationBarLayout == null) {
+            return null;
+        }
         return mLocationBarLayout.getVoiceRecognitionHandler();
     }