Add ExternalPrerenderRequestHandler and related API

chrome/browser/prerender/external_prerender_handler_android.cc

+// Copyright (c) 2013 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/prerender/external_prerender_handler_android.h"
+
+#include "base/android/jni_android.h"
+#include "base/android/jni_string.h"
+#include "base/strings/string16.h"
+#include "base/strings/utf_string_conversions.h"
+#include "chrome/browser/browser_process.h"
+#include "chrome/browser/prerender/prerender_handle.h"
+#include "chrome/browser/prerender/prerender_manager.h"
+#include "chrome/browser/prerender/prerender_manager_factory.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/profiles/profile_android.h"
+#include "content/public/browser/web_contents.h"
+
+#include "jni/ExternalPrerenderHandler_jni.h"
+
+using base::android::ConvertJavaStringToUTF16;
+
+namespace prerender {
+
+bool ExternalPrerenderHandlerAndroid::AddPrerender(JNIEnv* env,
+                                                   jobject obj,
+                                                   jobject jprofile,
+                                                   jint web_contents_ptr,
+                                                   jstring jurl,
+                                                   jstring jreferrer,
+                                                   jint width,
+                                                   jint height) {
+  Profile* profile = ProfileAndroid::FromProfileAndroid(jprofile);
+
+  GURL url = GURL(ConvertJavaStringToUTF16(env, jurl));
+  if (!url.is_valid())
+    return false;
+
+  GURL referrer_url = GURL(ConvertJavaStringToUTF16(env, jreferrer));
+  content::Referrer referrer = referrer_url.is_valid() ?
+      content::Referrer(referrer_url, WebKit::WebReferrerPolicyDefault) :
+      content::Referrer();
+
+  PrerenderManager* prerender_manager =
+      prerender::PrerenderManagerFactory::GetForProfile(profile);
+  if (!prerender_manager)
+    return false;
+  content::WebContents* web_contents =
+      reinterpret_cast<content::WebContents*>(web_contents_ptr);
+  if (prerender_handle_.get()) {
+    prerender_handle_->OnNavigateAway();
+    // The PrerenderHandle is now owned by the PrerenderManager.

[cbentzel, 2013/11/01 20:22:09]

I'm confused - where do you see that the PrerenderHandle is owned by the
PrerenderManager? This looks like a leak.

When the PrerenderManager creates a PrerenderHandle (such as AddPrerender*
calls) the returned pointer is owned by the caller.

OnNavigateAway will keep the PrerenderData/PrerenderContents alive. However, the
handle is still owned externally (and can be deleted once OnNavigateAWay is
called).

[Yusuf, 2013/11/04 22:27:49]

Done.

+    ignore_result(prerender_handle_.release());
+  }
+  prerender_handle_.reset(
+      prerender_manager->AddPrerenderFromExternalRequest(
+          url,
+          referrer,
+          web_contents->GetController().GetDefaultSessionStorageNamespace(),
+          gfx::Size(width, height)));
+  if (!prerender_handle_)
+    return false;
+  return true;
+}
+
+void ExternalPrerenderHandlerAndroid::CancelCurrentPrerender(JNIEnv* env,
+                                                             jobject object) {
+  if (prerender_handle_)
+    prerender_handle_->OnCancel();

[cbentzel, 2013/11/01 20:22:09]

You need to reset the prerender_handle_ here after canceling it as well.
Definitely don't want Cancel called on the same handle multiple times - and
CancelCurrentPrerender followed by AddPrerender also won't behave how you want.

[Yusuf, 2013/11/04 22:27:49]

Done.

+}
+
+static jboolean HasPrerenderedUrl(JNIEnv* env,
+                                  jclass clazz,
+                                  jobject jprofile,
+                                  jstring jurl,
+                                  jint web_contents_ptr) {
+  if (jurl == NULL)
+    return false;
+
+  Profile* profile = ProfileAndroid::FromProfileAndroid(jprofile);
+  GURL url = GURL(ConvertJavaStringToUTF16(env, jurl));
+  if (!url.is_valid())
+    return false;
+  prerender::PrerenderManager* prerender_manager =
+          prerender::PrerenderManagerFactory::GetForProfile(profile);
+  if (!prerender_manager)
+    return false;
+  content::WebContents* web_contents =
+      reinterpret_cast<content::WebContents*>(web_contents_ptr);
+  return prerender_manager->HasPrerenderedUrl(url, web_contents);
+}
+
+ExternalPrerenderHandlerAndroid::ExternalPrerenderHandlerAndroid() {}
+
+ExternalPrerenderHandlerAndroid::~ExternalPrerenderHandlerAndroid() {}
+
+static jint Init(JNIEnv* env,
+                 jclass clazz) {
+  ExternalPrerenderHandlerAndroid* external_handler =
+      new ExternalPrerenderHandlerAndroid();
+  return reinterpret_cast<jint>(external_handler);
+}
+
+bool ExternalPrerenderHandlerAndroid::RegisterExternalPrerenderHandlerAndroid(
+    JNIEnv* env) {
+  return RegisterNativesImpl(env);
+}
+
+} // namespace prerender