Introduce ManifestUpgradeDetector for WebAPK to detect web manifest changes.

chrome/browser/android/webapk/manifest_upgrade_detector.cc

Index: chrome/browser/android/webapk/manifest_upgrade_detector.cc
diff --git a/chrome/browser/android/webapk/manifest_upgrade_detector.cc b/chrome/browser/android/webapk/manifest_upgrade_detector.cc
new file mode 100644
index 0000000000000000000000000000000000000000..646c658baa14670ef17b78700495277563aed744
--- /dev/null
+++ b/chrome/browser/android/webapk/manifest_upgrade_detector.cc
@@ -0,0 +1,149 @@
+// Copyright 2016 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/android/webapk/manifest_upgrade_detector.h"
+
+#include <jni.h>
+
+#include "base/android/jni_android.h"
+#include "base/android/jni_string.h"
+#include "chrome/browser/android/shortcut_info.h"
+#include "content/public/browser/render_frame_host.h"
+#include "content/public/browser/web_contents.h"
+#include "content/public/common/manifest.h"
+#include "jni/ManifestUpgradeDetector_jni.h"
+#include "url/gurl.h"
+
+namespace {
+
+// Returns whether the given |url| is within the scope of the |scope| url.
+bool IsInScope(const GURL& url, const GURL& scope) {
+  return base::StartsWith(url.spec(), scope.spec(),
+                         base::CompareCase::SENSITIVE);
+}
+
+}  // namespace
+
+jlong Initialize(JNIEnv* env,
+                 const JavaParamRef<jobject>& obj,
+                 const JavaParamRef<jobject>& java_web_contents,
+                 const JavaParamRef<jstring>& java_scope,
+                 const JavaParamRef<jstring>& java_start_url,
+                 const JavaParamRef<jstring>& java_web_manifest_url) {
+  content::WebContents* web_contents =
+      content::WebContents::FromJavaWebContents(java_web_contents);
+  GURL scope(base::android::ConvertJavaStringToUTF8(env, java_scope));
+  GURL start_url(base::android::ConvertJavaStringToUTF8(env, java_start_url));
+  GURL web_manifest_url(base::android::ConvertJavaStringToUTF8(
+      env, java_web_manifest_url));
+  ManifestUpgradeDetector* manifest_upgrade_detector =
+      new ManifestUpgradeDetector(env, obj, web_contents, scope, start_url,
+                                  web_manifest_url);
+  return reinterpret_cast<intptr_t>(manifest_upgrade_detector);
+}
+
+ManifestUpgradeDetector::ManifestUpgradeDetector(
+    JNIEnv* env,
+    jobject obj,
+    content::WebContents* web_contents,
+    const GURL& scope,
+    const GURL& start_url,
+    const GURL& web_manifest_url)
+    : content::WebContentsObserver(web_contents),
+      started_(false),
+      scope_(scope),
+      start_url_(start_url),

[Yaron, 2016/07/20 02:27:59]

where is this used?

[Xi Han, 2016/07/20 18:55:00]

Thanks for catching this. I forgot why I initially passed it  to native, but now
it isn't used anymore.

+      web_manifest_url_(web_manifest_url),
+      weak_ptr_factory_(this) {
+  java_ref_.Reset(env, obj);
+}
+
+ManifestUpgradeDetector::~ManifestUpgradeDetector() {
+}
+
+// static
+bool ManifestUpgradeDetector::Register(JNIEnv* env) {
+  return RegisterNativesImpl(env);
+}
+
+void ManifestUpgradeDetector::ReplaceWebContents(
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj,
+    const JavaParamRef<jobject>& jweb_contents) {
+  content::WebContents* web_contents =
+      content::WebContents::FromJavaWebContents(jweb_contents);
+  content::WebContentsObserver::Observe(web_contents);
+}
+
+void ManifestUpgradeDetector::Destroy(JNIEnv* env,
+                                      const JavaParamRef<jobject>& obj) {
+  delete this;
+}
+
+void ManifestUpgradeDetector::Start(JNIEnv* env,
+                                    const JavaParamRef<jobject>& obj) {
+  started_ = true;
+}
+
+void ManifestUpgradeDetector::DidFinishLoad(
+    content::RenderFrameHost* render_frame_host,
+    const GURL& validated_url) {
+  if (render_frame_host->GetParent())
+    return;
+  if (!started_ || !IsInScope(validated_url, scope_))
+    return;
+
+  content::WebContents* web_contents =
+      content::WebContentsObserver::web_contents();

[pkotwicz, 2016/07/19 18:02:39]

Nit: Remove lines 97 - 98 and replace line 99 with:
web_contents()->GetManifest(

[Xi Han, 2016/07/20 18:55:00]

Done.

+  web_contents->GetManifest(
+      base::Bind(&ManifestUpgradeDetector::OnDidGetManifest,
+                weak_ptr_factory_.GetWeakPtr()));

[pkotwicz, 2016/07/19 18:02:39]

Nit: indentation looks off. (Not sure though)

[Xi Han, 2016/07/20 18:55:00]

Done.

+}
+
+void ManifestUpgradeDetector::OnDidGetManifest(
+    const GURL& manifest_url,
+    const content::Manifest& manifest) {
+  // If the manifest is empty, it means the current WebContents doesn't
+  // associate with a Web Manifest. In such case, we ignore the empty manifest
+  // and continue observing the WebContents's loading until we find a page that

[Yaron, 2016/07/20 02:27:59]

i'm a bit confused by this. A page should only have one manifest - or does this
apply across multiple page loads?

[Xi Han, 2016/07/20 18:55:00]

Yes, it aims to handle multiple pages navigation within a webapp, since we can't
assume there is no such case occurs. For example, user clicks an arbitrary link
within the scope of a WebAPK, and it bounces into the WebAPK. The WebAPK is
launched not from the start url, but a url that doesn't link to its web
manifest.

+  // links to the Web Manifest that we are looking for.
+  // If the manifest URL is different from the current one, we will continue
+  // observing too. It is based on our assumption that it is invalid for
+  // web developers to cahnge the Web Manifest location. When it does

[pkotwicz, 2016/07/19 18:02:39]

cahnge -> change

[Xi Han, 2016/07/20 18:55:00]

Done.

+  // change, we will treat the new Web Manifest as the one of another WebAPK.

[pkotwicz, 2016/07/19 18:02:39]

This logic should probably be unit tested

[Xi Han, 2016/07/20 18:55:00]

Done.

+  if (manifest.IsEmpty() || web_manifest_url_ != manifest_url)
+    return;
+
+  started_ = false;
+
+  ShortcutInfo info(GURL::EmptyGURL());
+  info.UpdateFromManifest(manifest);
+  info.manifest_url = manifest_url;
+
+  OnDataAvailable(info);
+}
+
+void ManifestUpgradeDetector::OnDataAvailable(const ShortcutInfo& info) {
+  JNIEnv* env = base::android::AttachCurrentThread();
+
+  ScopedJavaLocalRef<jstring> java_url =
+      base::android::ConvertUTF8ToJavaString(env, info.url.spec());
+  ScopedJavaLocalRef<jstring> java_scope =
+      base::android::ConvertUTF8ToJavaString(env, info.scope.spec());
+  ScopedJavaLocalRef<jstring> java_name =
+      base::android::ConvertUTF16ToJavaString(env, info.name);
+  ScopedJavaLocalRef<jstring> java_short_name =
+      base::android::ConvertUTF16ToJavaString(env, info.short_name);
+
+  Java_ManifestUpgradeDetector_onDataAvailable(

[pkotwicz, 2016/07/19 18:02:39]

Nit: 4 spaces indentation

[Xi Han, 2016/07/20 18:55:00]

Done.

+    env, java_ref_.obj(),
+    java_url.obj(),
+    java_scope.obj(),
+    java_name.obj(),
+    java_short_name.obj(),
+    info.display,
+    info.orientation,
+    info.theme_color,
+    info.background_color);
+}