Add a check for null returns from SpellChekerSessonBridge#create().

chrome/browser/spellchecker/spellchecker_session_bridge_android.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/spellchecker/spellchecker_session_bridge_android.h"
 
 #include "base/android/jni_array.h"
 #include "base/android/jni_string.h"
 #include "chrome/common/spellcheck_messages.h"
 #include "chrome/common/spellcheck_result.h"
 #include "content/public/browser/render_process_host.h"
 #include "jni/SpellCheckerSessionBridge_jni.h"
 
 SpellCheckerSessionBridge::SpellCheckerSessionBridge(int render_process_id)
     : render_process_id_(render_process_id) {}
 
 SpellCheckerSessionBridge::~SpellCheckerSessionBridge() {}
 
 // static
 bool SpellCheckerSessionBridge::RegisterJNI(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 void SpellCheckerSessionBridge::RequestTextCheck(int route_id,
                                                  int identifier,
                                                  const base::string16& text) {
+  // SpellCheckerSessionBridge#create() will return null if spell checker
+  // service is unavailable.
+  if (java_object_initialization_failed_)
+    return;
+
   // RequestTextCheck IPC arrives at the message filter before
   // ToggleSpellCheck IPC when the user focuses an input field that already
   // contains completed text.  We need to initialize the spellchecker here
   // rather than in response to ToggleSpellCheck so that the existing text
   // will be spellchecked immediately.
   if (java_object_.is_null()) {
     java_object_.Reset(Java_SpellCheckerSessionBridge_create(
         base::android::AttachCurrentThread(),
         reinterpret_cast<intptr_t>(this)));
+    if (java_object_.is_null()) {
+      java_object_initialization_failed_ = true;
+      return;
+    }
   }
 
   // Save incoming requests to run at the end of the currently active request.
   // If multiple requests arrive during one active request, only the most
   // recent request will run (the others get overwritten).
   if (active_request_) {
     pending_request_.reset(new SpellingRequest(route_id, identifier, text));
     return;
   }
 
@@ skipping 45 matching lines @@
   java_object_.Reset();
 }
 
 SpellCheckerSessionBridge::SpellingRequest::SpellingRequest(
     int route_id,
     int identifier,
     const base::string16& text)
     : route_id(route_id), identifier(identifier), text(text) {}
 
 SpellCheckerSessionBridge::SpellingRequest::~SpellingRequest() {}