Chrome talks to Play to install WebAPKs.

chrome/browser/android/webapk/webapk_installer.cc

 // 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/webapk_installer.h"
 
 #include "base/android/build_info.h"
 #include "base/android/jni_android.h"
 #include "base/android/jni_string.h"
 #include "base/android/path_utils.h"
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "base/memory/ref_counted.h"
+#include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/task_runner_util.h"
 #include "base/threading/sequenced_worker_pool.h"
 #include "chrome/browser/android/shortcut_helper.h"
 #include "chrome/browser/android/webapk/webapk.pb.h"
 #include "chrome/browser/android/webapk/webapk_icon_hasher.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/chrome_switches.h"
@@ skipping 282 matching lines @@
       env, java_ref_, java_file_path, java_package_name);
 }
 
 bool WebApkInstaller::StartUpdateUsingDownloadedWebApk(
     JNIEnv* env,
     const base::android::ScopedJavaLocalRef<jstring>& java_file_path) {
   return Java_WebApkInstaller_updateAsyncFromNative(
       env, java_ref_, java_file_path);
 }
 
+bool WebApkInstaller::HasGooglePlayWebApkInstallDelegate() {
+  JNIEnv* env = base::android::AttachCurrentThread();
+  return Java_WebApkInstaller_hasGooglePlayWebApkInstallDelegate(
+      env, java_ref_);
+}
+
+bool WebApkInstaller::InstallOrUpdateWebApkFromGooglePlay(
+    const std::string& package_name,
+    int version,
+    const std::string& token) {
+  webapk_package_ = package_name;
+
+  JNIEnv* env = base::android::AttachCurrentThread();
+  base::android::ScopedJavaLocalRef<jstring> java_webapk_package =
+      base::android::ConvertUTF8ToJavaString(env, webapk_package_);
+  base::android::ScopedJavaLocalRef<jstring> java_title =
+      base::android::ConvertUTF16ToJavaString(env, shortcut_info_.user_title);
+  base::android::ScopedJavaLocalRef<jstring> java_token =
+      base::android::ConvertUTF8ToJavaString(env, token);
+
+  if (task_type_ == WebApkInstaller::INSTALL) {
+    return Java_WebApkInstaller_installWebApkFromGooglePlayAsync(
+        env, java_ref_, java_webapk_package, version, java_title, java_token);
+  } else {
+    return Java_WebApkInstaller_updateAsyncFromGooglePlay(
+        env, java_ref_, java_webapk_package, version, java_title, java_token);
+  }
+}
+
 void WebApkInstaller::OnURLFetchComplete(const net::URLFetcher* source) {
   timer_.Stop();
 
   if (!source->GetStatus().is_success() ||
       source->GetResponseCode() != net::HTTP_OK) {
     OnFailure();
     return;
   }
 
   std::string response_string;
   source->GetResponseAsString(&response_string);
 
   std::unique_ptr<webapk::WebApkResponse> response(
       new webapk::WebApkResponse);
   if (!response->ParseFromString(response_string)) {
     OnFailure();
     return;
   }
 
   GURL signed_download_url(response->signed_download_url());
   if (!signed_download_url.is_valid() || response->package_name().empty()) {
     OnFailure();
     return;
   }
+
+  if (HasGooglePlayWebApkInstallDelegate()) {
+    int version = 1;

[dominickn, 2016/12/08 03:31:26]

Set this to 0 by default, and check the return value of base::StringToInt. You
should fail if the conversion didn't succeed.

[Xi Han, 2016/12/08 18:03:07]

Good catch, but maybe we still want to continue the play install in this case.
It is because the version is required by Play and they only need it when showing
a notification during installation. It would be fine if the version of the
WebAPK is just a default "1", I guess. The notification will disappear soon.

+    base::StringToInt(response->version(), &version);
+    if (!InstallOrUpdateWebApkFromGooglePlay(
+        response->package_name(), version, response->token())) {
+      OnFailure();
+    }
+    return;
+  }
+
   OnGotWebApkDownloadUrl(signed_download_url, response->package_name());
 }
 
 void WebApkInstaller::DownloadAppIconAndComputeMurmur2Hash() {
   // Safeguard. WebApkIconHasher crashes if asked to fetch an invalid URL.
   if (!shortcut_info_.best_icon_url.is_valid()) {
     OnFailure();
     return;
   }
 
@@ skipping 163 matching lines @@
 
 void WebApkInstaller::OnSuccess() {
   finish_callback_.Run(true, webapk_package_);
   delete this;
 }
 
 void WebApkInstaller::OnFailure() {
   finish_callback_.Run(false, webapk_package_);
   delete this;
 }