Add hooks for BeforeInstallPromptEvent to be redispatched.

Source/modules/app_banner/BeforeInstallPromptEvent.cpp

 // 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 "config.h"
 #include "modules/app_banner/BeforeInstallPromptEvent.h"
 
 #include "bindings/core/v8/CallbackPromiseAdapter.h"
 #include "bindings/core/v8/ScriptPromiseResolver.h"
 #include "modules/app_banner/AppBannerPromptResult.h"
 #include "modules/app_banner/BeforeInstallPromptEventInit.h"
 #include "public/platform/modules/app_banner/WebAppBannerClient.h"
 
 namespace blink {
 
 BeforeInstallPromptEvent::BeforeInstallPromptEvent()
 {
 }
 
 BeforeInstallPromptEvent::BeforeInstallPromptEvent(const AtomicString& name, const Vector<String>& platforms, int requestId, WebAppBannerClient* client)
     : Event(name, false, true)
     , m_platforms(platforms)
     , m_requestId(requestId)
     , m_client(client)
+    , m_redispatched(false)
 {
 }
 
 BeforeInstallPromptEvent::BeforeInstallPromptEvent(const AtomicString& name, const BeforeInstallPromptEventInit& init)
     : Event(name, false, true)
     , m_platforms(init.platforms())
     , m_requestId(-1)
     , m_client(nullptr)
+    , m_redispatched(false)
 {
 }
 
 BeforeInstallPromptEvent::~BeforeInstallPromptEvent()
 {
 }
 
 Vector<String> BeforeInstallPromptEvent::platforms() const
 {
     return m_platforms;
 }
 
 ScriptPromise BeforeInstallPromptEvent::userChoice(ScriptState* scriptState)
 {
     if (m_userChoice.isEmpty() && m_client) {
         ASSERT(m_requestId != -1);
         RefPtrWillBeRawPtr<ScriptPromiseResolver> resolver = ScriptPromiseResolver::create(scriptState);
         m_userChoice = resolver->promise();
         m_client->registerBannerCallbacks(m_requestId, new CallbackPromiseAdapter<AppBannerPromptResult, void>(resolver));
     }
 
     return m_userChoice;
 }
 
 const AtomicString& BeforeInstallPromptEvent::interfaceName() const
 {
     return EventNames::BeforeInstallPromptEvent;
 }
 
+void BeforeInstallPromptEvent::prompt()
+{
+    // This will silently fail if preventDefault() has not previously been
+    // called (the event cannot be redispatched if it has not been stopped).
+    // It will also silently fail if the event has already been redispatched.

[mlamouri (slow - plz ping), 2015/06/06 21:40:55]

Why silently failing? Why not having prompt() return a Promise<> and reject the
promise if the state isn't the expected one? It will also give leeway for UA to
reject the prompt() request.

+    if (m_client && defaultPrevented() && !m_redispatched) {
+        ASSERT(m_requestId != -1);
+        m_redispatched = true;
+        m_client->resolveEventRedispatch(m_requestId);
+    }
+}
+
 } // namespace blink