Make inline install for disabled items just re-enable

chrome/browser/extensions/webstore_standalone_installer.cc

 // Copyright (c) 2012 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/extensions/webstore_standalone_installer.h"
 
 #include "base/values.h"
 #include "chrome/browser/extensions/crx_installer.h"
 #include "chrome/browser/extensions/extension_install_prompt.h"
 #include "chrome/browser/extensions/extension_install_ui.h"
+#include "chrome/browser/extensions/extension_prefs.h"
 #include "chrome/browser/extensions/extension_service.h"
+#include "chrome/browser/extensions/extension_system.h"
 #include "chrome/browser/extensions/webstore_data_fetcher.h"
 #include "chrome/browser/profiles/profile.h"
 #include "content/public/browser/web_contents.h"
 #include "extensions/common/extension.h"
 #include "url/gurl.h"
 
 using content::WebContents;
 
 namespace extensions {
 
 const char kManifestKey[] = "manifest";
 const char kIconUrlKey[] = "icon_url";
 const char kLocalizedNameKey[] = "localized_name";
 const char kLocalizedDescriptionKey[] = "localized_description";
 const char kUsersKey[] = "users";
 const char kShowUserCountKey[] = "show_user_count";
 const char kAverageRatingKey[] = "average_rating";
 const char kRatingCountKey[] = "rating_count";
 
 const char kInvalidWebstoreItemId[] = "Invalid Chrome Web Store item ID";
 const char kWebstoreRequestError[] =
     "Could not fetch data from the Chrome Web Store";
 const char kInvalidWebstoreResponseError[] = "Invalid Chrome Web Store reponse";
 const char kInvalidManifestError[] = "Invalid manifest";
 const char kUserCancelledError[] = "User cancelled install";
-
+const char kExtensionIsBlacklisted[] = "Extension is blacklisted";
 
 WebstoreStandaloneInstaller::WebstoreStandaloneInstaller(
     const std::string& webstore_item_id,
     Profile* profile,
     const Callback& callback)
     : id_(webstore_item_id),
       callback_(callback),
       profile_(profile),
       install_source_(WebstoreInstaller::INSTALL_SOURCE_INLINE),
       show_user_count_(true),
@@ skipping 182 matching lines @@
     const std::string& error_message) {
   CompleteInstall(error_message);
 }
 
 void WebstoreStandaloneInstaller::InstallUIProceed() {
   if (!CheckRequestorAlive()) {
     CompleteInstall(std::string());
     return;
   }
 
+  ExtensionService* extension_service =
+      ExtensionSystem::Get(profile_)->extension_service();
+  const Extension* extension =
+      extension_service->GetExtensionById(id_, true /* include disabled */);
+  if (extension) {
+    std::string install_result;  // Empty string for install success.
+    if (!extension_service->IsExtensionEnabled(id_)) {
+      if (!ExtensionPrefs::Get(profile_)->IsExtensionBlacklisted(id_)) {
+        // If the extension is installed but disabled, and not blacklisted,
+        // enable it.
+        extension_service->EnableExtension(id_);
+      } else {  // Don't install a blacklisted extension.
+        install_result = kExtensionIsBlacklisted;
+      }
+    }  // else extension is installed and enabled; no work to be done.
+    CompleteInstall(install_result);
+    return;
+  }
+
   scoped_ptr<WebstoreInstaller::Approval> approval = CreateApproval();
 
   scoped_refptr<WebstoreInstaller> installer = new WebstoreInstaller(
       profile_,
       this,
       &(GetWebContents()->GetController()),
       id_,
       approval.Pass(),
       install_source_);
   installer->Start();
@@ skipping 55 matching lines @@
   // Balanced in InstallUIAbort or indirectly in InstallUIProceed via
   // OnExtensionInstallSuccess or OnExtensionInstallFailure.
   AddRef();
 
   install_ui_ = CreateInstallUI();
   install_ui_->ConfirmStandaloneInstall(
       this, localized_extension_for_display_.get(), &icon_, *install_prompt_);
 }
 
 }  // namespace extensions