Update the EphemeralAppLauncher for use by the webstorePrivate API

chrome/browser/apps/ephemeral_app_launcher.cc

 // Copyright 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/apps/ephemeral_app_launcher.h"
 
+#include "base/command_line.h"
+#include "base/strings/utf_string_conversions.h"
+#include "chrome/browser/extensions/extension_install_checker.h"
 #include "chrome/browser/extensions/extension_install_prompt.h"
 #include "chrome/browser/extensions/extension_util.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/extensions/application_launch.h"
 #include "chrome/browser/ui/extensions/extension_enable_flow.h"
+#include "chrome/common/chrome_switches.h"
 #include "content/public/browser/web_contents.h"
+#include "extensions/browser/extension_prefs.h"
 #include "extensions/browser/extension_registry.h"
+#include "extensions/browser/extension_system.h"
+#include "extensions/browser/management_policy.h"
 #include "extensions/common/permissions/permissions_data.h"
 
 using content::WebContents;
 using extensions::Extension;
+using extensions::ExtensionInstallChecker;
+using extensions::ExtensionPrefs;
 using extensions::ExtensionRegistry;
+using extensions::ExtensionSystem;
+using extensions::ManagementPolicy;
 using extensions::WebstoreInstaller;
+namespace webstore_install = extensions::webstore_install;
 
 namespace {
 
 const char kInvalidManifestError[] = "Invalid manifest";
-const char kExtensionTypeError[] = "Ephemeral extensions are not permitted";
-const char kLaunchAbortedError[] = "Launch aborted";
+const char kExtensionTypeError[] = "Cannot launch an extension";
+const char kUserCancelledError[] = "Launch cancelled by the user";
+const char kBlacklistedError[] = "App is blacklisted for malware";
+const char kRequirementsError[] = "App has missing requirements";
+const char kFeatureDisabledError[] = "Launching ephemeral apps is not enabled";
+const char kMissingAppError[] = "App is not installed";
+const char kAppDisabledError[] = "App is disabled";
 
 Profile* ProfileForWebContents(content::WebContents* contents) {
   if (!contents)
     return NULL;
 
   return Profile::FromBrowserContext(contents->GetBrowserContext());
 }
 
 gfx::NativeWindow NativeWindowForWebContents(content::WebContents* contents) {
   if (!contents)
     return NULL;
 
   return contents->GetTopLevelNativeWindow();
 }
 
+// Check whether an extension can be launched. The extension does not need to
+// be currently installed.
+bool CheckCommonLaunchCriteria(Profile* profile,
+                               const extensions::Extension* extension,
+                               webstore_install::Result* reason,
+                               std::string* error) {
+  // Only apps can be launched.
+  if (!extension->is_app()) {
+    *reason = webstore_install::LAUNCH_UNSUPPORTED_EXTENSION_TYPE;
+    *error = kExtensionTypeError;
+    return false;
+  }
+
+  // Do not launch apps blocked by management policies.
+  ManagementPolicy* management_policy =
+      ExtensionSystem::Get(profile)->management_policy();
+  base::string16 policy_error;
+  if (!management_policy->UserMayLoad(extension, &policy_error)) {
+    *reason = webstore_install::BLOCKED_BY_POLICY;
+    *error = base::UTF16ToUTF8(policy_error);
+    return false;
+  }
+
+  return true;
+}
+
 }  // namespace
 
 // static
-scoped_refptr<EphemeralAppLauncher>
-EphemeralAppLauncher::CreateForLauncher(
+bool EphemeralAppLauncher::IsFeatureEnabled() {
+  return CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kEnableEphemeralApps);
+}
+
+// static
+scoped_refptr<EphemeralAppLauncher> EphemeralAppLauncher::CreateForLauncher(
     const std::string& webstore_item_id,
     Profile* profile,
     gfx::NativeWindow parent_window,
-    const Callback& callback) {
+    const LaunchCallback& callback) {
   scoped_refptr<EphemeralAppLauncher> installer =
       new EphemeralAppLauncher(webstore_item_id,
                                profile,
                                parent_window,
                                callback);
   installer->set_install_source(WebstoreInstaller::INSTALL_SOURCE_APP_LAUNCHER);
   return installer;
 }
 
 // static
-scoped_refptr<EphemeralAppLauncher>
-EphemeralAppLauncher::CreateForLink(
+scoped_refptr<EphemeralAppLauncher> EphemeralAppLauncher::CreateForWebContents(
     const std::string& webstore_item_id,
-    content::WebContents* web_contents) {
+    content::WebContents* web_contents,
+    const LaunchCallback& callback) {
   scoped_refptr<EphemeralAppLauncher> installer =
-      new EphemeralAppLauncher(webstore_item_id,
-                               web_contents,
-                               Callback());
+      new EphemeralAppLauncher(webstore_item_id, web_contents, callback);
   installer->set_install_source(WebstoreInstaller::INSTALL_SOURCE_OTHER);
   return installer;
 }
 
 void EphemeralAppLauncher::Start() {
+  if (!IsFeatureEnabled()) {
+    InvokeCallback(webstore_install::LAUNCH_FEATURE_DISABLED,
+                   kFeatureDisabledError);
+    return;
+  }
+
+  // Check whether the app already exists in extension system before downloading
+  // from the webstore.
   const Extension* extension =
       ExtensionRegistry::Get(profile())
           ->GetExtensionById(id(), ExtensionRegistry::EVERYTHING);
   if (extension) {
+    webstore_install::Result result = webstore_install::UNKNOWN_ERROR;
+    std::string error;
+    if (!CanLaunchInstalledApp(extension, &result, &error)) {
+      InvokeCallback(result, error);
+      return;
+    }
+
     if (extensions::util::IsAppLaunchableWithoutEnabling(extension->id(),
                                                          profile())) {
       LaunchApp(extension);
-      InvokeCallback(std::string());
+      InvokeCallback(webstore_install::SUCCESS, std::string());
       return;
     }
 
-    // The ephemeral app may have been updated and disabled as it requests
-    // more permissions. In this case we should always prompt before
-    // launching.
-    extension_enable_flow_.reset(
-        new ExtensionEnableFlow(profile(), extension->id(), this));
-    if (web_contents())
-      extension_enable_flow_->StartForWebContents(web_contents());
-    else
-      extension_enable_flow_->StartForNativeWindow(parent_window_);
-
-    // Keep this object alive until the enable flow is complete.
-    AddRef();  // Balanced in WebstoreStandaloneInstaller::CompleteInstall.
+    EnableInstalledApp(extension);
     return;
   }
 
-  // Fetch the app from the webstore.
+  // Install the app ephemerally and launch when complete.
   BeginInstall();
 }
 
 EphemeralAppLauncher::EphemeralAppLauncher(const std::string& webstore_item_id,
                                            Profile* profile,
                                            gfx::NativeWindow parent_window,
-                                           const Callback& callback)
-    : WebstoreStandaloneInstaller(webstore_item_id, profile, callback),
+                                           const LaunchCallback& callback)
+    : WebstoreStandaloneInstaller(webstore_item_id, profile, Callback()),
+      launch_callback_(callback),
       parent_window_(parent_window),
       dummy_web_contents_(
           WebContents::Create(WebContents::CreateParams(profile))) {
 }
 
 EphemeralAppLauncher::EphemeralAppLauncher(const std::string& webstore_item_id,
                                            content::WebContents* web_contents,
-                                           const Callback& callback)
+                                           const LaunchCallback& callback)
     : WebstoreStandaloneInstaller(webstore_item_id,
                                   ProfileForWebContents(web_contents),
-                                  callback),
+                                  Callback()),
       content::WebContentsObserver(web_contents),
+      launch_callback_(callback),
       parent_window_(NativeWindowForWebContents(web_contents)) {
 }
 
 EphemeralAppLauncher::~EphemeralAppLauncher() {}
 
+bool EphemeralAppLauncher::CanLaunchInstalledApp(
+    const extensions::Extension* extension,
+    webstore_install::Result* reason,
+    std::string* error) {
+  if (!CheckCommonLaunchCriteria(profile(), extension, reason, error))
+    return false;
+
+  // Do not launch blacklisted apps.
+  if (ExtensionPrefs::Get(profile())->IsExtensionBlacklisted(extension->id())) {
+    *reason = webstore_install::BLACKLISTED;
+    *error = kBlacklistedError;
+    return false;
+  }
+
+  // If the app has missing requirements, it cannot be launched.
+  if (!extensions::util::IsAppLaunchable(extension->id(), profile())) {
+    *reason = webstore_install::REQUIREMENT_VIOLATIONS;
+    *error = kRequirementsError;
+    return false;
+  }
+
+  return true;
+}
+
+void EphemeralAppLauncher::EnableInstalledApp(const Extension* extension) {
+  extension_enable_flow_.reset(
+      new ExtensionEnableFlow(profile(), extension->id(), this));
+  if (web_contents())
+    extension_enable_flow_->StartForWebContents(web_contents());
+  else
+    extension_enable_flow_->StartForNativeWindow(parent_window_);
+
+  // Keep this object alive until the enable flow is complete. Either
+  // ExtensionEnableFlowFinished() or ExtensionEnableFlowAborted() will be
+  // called.
+  AddRef();
+}
+
+void EphemeralAppLauncher::MaybeLaunchApp() {
+  webstore_install::Result result = webstore_install::UNKNOWN_ERROR;
+  std::string error;
+
+  ExtensionRegistry* registry = ExtensionRegistry::Get(profile());
+  const Extension* extension =
+      registry->GetExtensionById(id(), ExtensionRegistry::EVERYTHING);
+  if (extension) {
+    // Although the installation was successful, the app may not be
+    // launchable.
+    if (registry->enabled_extensions().Contains(extension->id())) {
+      result = webstore_install::SUCCESS;
+      LaunchApp(extension);
+    } else {
+      error = kAppDisabledError;
+      // Determine why the app cannot be launched.
+      CanLaunchInstalledApp(extension, &result, &error);
+    }
+  } else {
+    // The extension must be present in the registry if installed.
+    NOTREACHED();
+    error = kMissingAppError;
+  }
+
+  InvokeCallback(result, error);
+}
+
 void EphemeralAppLauncher::LaunchApp(const Extension* extension) const {
-  DCHECK(extension);
-  if (!extension->is_app()) {
-    LOG(ERROR) << "Unable to launch extension " << extension->id()
-               << ". It is not an app.";
-    return;
-  }
+  DCHECK(extension && extension->is_app() &&
+         ExtensionRegistry::Get(profile())
+             ->GetExtensionById(extension->id(), ExtensionRegistry::ENABLED));
 
   AppLaunchParams params(profile(), extension, NEW_FOREGROUND_TAB);
   params.desktop_type =
       chrome::GetHostDesktopTypeForNativeWindow(parent_window_);
   OpenApplication(params);
 }
 
+void EphemeralAppLauncher::InvokeCallback(webstore_install::Result result,
+                                          const std::string& error) {
+  if (!launch_callback_.is_null()) {
+    launch_callback_.Run(result, error);
+    launch_callback_.Reset();
+  }
+}
+
+void EphemeralAppLauncher::AbortLaunch(webstore_install::Result result,
+                                       const std::string& error) {
+  InvokeCallback(result, error);
+  WebstoreStandaloneInstaller::CompleteInstall(webstore_install::ABORTED,
+                                               std::string());
+}
+
+scoped_ptr<extensions::ExtensionInstallChecker>
+EphemeralAppLauncher::CreateInstallChecker() {
+  return make_scoped_ptr(new ExtensionInstallChecker(profile()));
+}
+
+void EphemeralAppLauncher::CheckEphemeralInstallPermitted() {
+  scoped_refptr<const Extension> extension = GetLocalizedExtensionForDisplay();
+  DCHECK(extension.get());  // Checked in OnManifestParsed().
+
+  install_checker_ = CreateInstallChecker();
+  DCHECK(install_checker_.get());
+
+  install_checker_->set_extension(extension);
+  install_checker_->Start(ExtensionInstallChecker::CHECK_BLACKLIST |
+                              ExtensionInstallChecker::CHECK_REQUIREMENTS,
+                          true,
+                          base::Bind(&EphemeralAppLauncher::OnInstallChecked,
+                                     base::Unretained(this)));
+}
+
+void EphemeralAppLauncher::OnInstallChecked(int check_failures) {
+  if (!CheckRequestorAlive()) {
+    AbortLaunch(webstore_install::UNKNOWN_ERROR, std::string());
+    return;
+  }
+
+  if (install_checker_->blacklist_state() == extensions::BLACKLISTED_MALWARE) {
+    AbortLaunch(webstore_install::BLACKLISTED, kBlacklistedError);
+    return;
+  }
+
+  if (!install_checker_->requirement_errors().empty()) {
+    AbortLaunch(webstore_install::REQUIREMENT_VIOLATIONS,
+                install_checker_->requirement_errors().front());
+    return;
+  }
+
+  // Proceed with the normal install flow.
+  ProceedWithInstallPrompt();
+}
+
 bool EphemeralAppLauncher::CheckRequestorAlive() const {
   return dummy_web_contents_.get() != NULL || web_contents() != NULL;
 }
 
 const GURL& EphemeralAppLauncher::GetRequestorURL() const {
   return GURL::EmptyGURL();
 }
 
 bool EphemeralAppLauncher::ShouldShowPostInstallUI() const {
   return false;
 }
 
 bool EphemeralAppLauncher::ShouldShowAppInstalledBubble() const {
   return false;
 }
 
 WebContents* EphemeralAppLauncher::GetWebContents() const {
   return web_contents() ? web_contents() : dummy_web_contents_.get();
 }
 
 scoped_refptr<ExtensionInstallPrompt::Prompt>
 EphemeralAppLauncher::CreateInstallPrompt() const {
-  DCHECK(extension_.get() != NULL);
+  const Extension* extension = localized_extension_for_display();
+  DCHECK(extension);  // Checked in OnManifestParsed().
 
   // Skip the prompt by returning null if the app does not need to display
   // permission warnings.
   extensions::PermissionMessages permissions =
-      extension_->permissions_data()->GetPermissionMessages();
+      extension->permissions_data()->GetPermissionMessages();
   if (permissions.empty())
     return NULL;
 
   return make_scoped_refptr(new ExtensionInstallPrompt::Prompt(
       ExtensionInstallPrompt::LAUNCH_PROMPT));
 }
 
 bool EphemeralAppLauncher::CheckInlineInstallPermitted(
     const base::DictionaryValue& webstore_data,
     std::string* error) const {
   *error = "";
   return true;
 }
 
 bool EphemeralAppLauncher::CheckRequestorPermitted(
     const base::DictionaryValue& webstore_data,
     std::string* error) const {
   *error = "";
   return true;
 }
 
-bool EphemeralAppLauncher::CheckInstallValid(
-    const base::DictionaryValue& manifest,
-    std::string* error) {
-  extension_ = Extension::Create(
-      base::FilePath(),
-      extensions::Manifest::INTERNAL,
-      manifest,
-      Extension::REQUIRE_KEY | Extension::FROM_WEBSTORE,
-      id(),
-      error);
-  if (!extension_.get()) {
-    *error = kInvalidManifestError;
-    return false;
+void EphemeralAppLauncher::OnManifestParsed() {
+  const Extension* extension = GetLocalizedExtensionForDisplay();
+  if (!extension) {
+    AbortLaunch(webstore_install::INVALID_MANIFEST, kInvalidManifestError);
+    return;
   }
 
-  if (!extension_->is_app()) {
-    *error = kExtensionTypeError;
-    return false;
+  webstore_install::Result result = webstore_install::UNKNOWN_ERROR;
+  std::string error;
+  if (!CheckCommonLaunchCriteria(profile(), extension, &result, &error)) {
+    AbortLaunch(result, error);
+    return;
   }
 
-  return true;
+  CheckEphemeralInstallPermitted();
 }
 
-scoped_ptr<ExtensionInstallPrompt>
-EphemeralAppLauncher::CreateInstallUI() {
+scoped_ptr<ExtensionInstallPrompt> EphemeralAppLauncher::CreateInstallUI() {
   if (web_contents())
     return make_scoped_ptr(new ExtensionInstallPrompt(web_contents()));
 
   return make_scoped_ptr(
       new ExtensionInstallPrompt(profile(), parent_window_, NULL));
 }
 
 scoped_ptr<WebstoreInstaller::Approval>
 EphemeralAppLauncher::CreateApproval() const {
   scoped_ptr<WebstoreInstaller::Approval> approval =
       WebstoreStandaloneInstaller::CreateApproval();
   approval->is_ephemeral = true;
   return approval.Pass();
 }
 
-void EphemeralAppLauncher::CompleteInstall(const std::string& error) {
-  if (error.empty()) {
-    const Extension* extension =
-        ExtensionRegistry::Get(profile())
-            ->GetExtensionById(id(), ExtensionRegistry::ENABLED);
-    if (extension)
-      LaunchApp(extension);
-  }
+void EphemeralAppLauncher::CompleteInstall(webstore_install::Result result,
+                                           const std::string& error) {
+  if (result == webstore_install::SUCCESS)
+    MaybeLaunchApp();
+  else if (!launch_callback_.is_null())
+    InvokeCallback(result, error);
 
-  WebstoreStandaloneInstaller::CompleteInstall(error);
+  WebstoreStandaloneInstaller::CompleteInstall(result, error);
 }
 
 void EphemeralAppLauncher::WebContentsDestroyed() {
+  launch_callback_.Reset();
   AbortInstall();
 }
 
 void EphemeralAppLauncher::ExtensionEnableFlowFinished() {
-  CompleteInstall(std::string());
+  MaybeLaunchApp();
+  Release();  // Matches the AddRef in EnableInstalledApp().
 }
 
 void EphemeralAppLauncher::ExtensionEnableFlowAborted(bool user_initiated) {
-  CompleteInstall(kLaunchAbortedError);
+  InvokeCallback(webstore_install::USER_CANCELLED, kUserCancelledError);
+  Release();  // Matches the AddRef in EnableInstalledApp().
 }