Implementing TabManager extensions API Discard Function.

chrome/browser/extensions/api/tabs/tabs_api.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/api/tabs/tabs_api.h"
 
 #include <stddef.h>
 #include <algorithm>
 #include <limits>
 #include <memory>
@@ skipping 56 matching lines @@
 #include "content/public/browser/navigation_controller.h"
 #include "content/public/browser/navigation_entry.h"
 #include "content/public/browser/notification_details.h"
 #include "content/public/browser/notification_source.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/render_widget_host_view.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/common/url_constants.h"
 #include "extensions/browser/app_window/app_window.h"
 #include "extensions/browser/extension_api_frame_id_map.h"
+#include "extensions/browser/extension_function.h"

[Devlin, 2016/07/21 15:39:21]

no need to include this, since it's included in the header.

[Anderson Silva, 2016/07/21 20:43:04]

Done.

 #include "extensions/browser/extension_function_dispatcher.h"
 #include "extensions/browser/extension_host.h"
 #include "extensions/browser/extension_zoom_request_client.h"
 #include "extensions/browser/file_reader.h"
 #include "extensions/browser/script_executor.h"
 #include "extensions/common/api/extension_types.h"
 #include "extensions/common/constants.h"
 #include "extensions/common/error_utils.h"
 #include "extensions/common/extension.h"
 #include "extensions/common/host_id.h"
@@ skipping 2074 matching lines @@
   api::tabs::ZoomSettings zoom_settings;
   ZoomModeToZoomSettings(zoom_mode, &zoom_settings);
   zoom_settings.default_zoom_factor.reset(new double(
       content::ZoomLevelToZoomFactor(zoom_controller->GetDefaultZoomLevel())));
 
   results_ = api::tabs::GetZoomSettings::Results::Create(zoom_settings);
   SendResponse(true);
   return true;
 }
 
+ExtensionFunction::ResponseAction TabsDiscardFunction::Run() {
+  std::unique_ptr<tabs::Discard::Params> params(
+      tabs::Discard::Params::Create(*args_));
+  EXTENSION_FUNCTION_VALIDATE(params);
+
+  WebContents* contents = nullptr;
+  Profile* profile = Profile::FromBrowserContext(browser_context());
+  // If |tab_id| is given, find the web_contents respective to it.
+  // Otherwise invoke discard function in TabManager with null web_contents
+  // that will discard the least important tab.
+  if (params->tab_id) {
+    int tab_id = *params->tab_id;
+    if (!GetTabById(tab_id, profile, include_incognito(), nullptr, nullptr,
+                    &contents, nullptr, &error_)) {
+      return RespondNow(Error(error_));
+    }
+  }
+  // Discard the tab.
+  contents =
+      g_browser_process->GetTabManager()->DiscardTabByExtension(contents);
+
+  // Create result to be returned. We have to return a Tab object and the
+  // success boolean, so create a default object and replace it with the
+  // real tab in case of success (contents is not null).

[Devlin, 2016/07/21 15:39:21]

Why not return undefined in the case of no tab discarded?  That would also
obviate the need for the extra boolean, right?

[Anderson Silva, 2016/07/21 20:43:04]

Done.
Removed the boolean. It was necessary before but with some design changes we
did, it isn't anymore.

+  bool success = !!contents;
+  std::unique_ptr<tabs::Tab> tab(new tabs::Tab);
+  if (success)
+    tab = ExtensionTabUtil::CreateTabObject(contents);
+  return RespondNow(
+      ArgumentList(tabs::Discard::Results::Create(*tab, success)));
+}
+
+TabsDiscardFunction::TabsDiscardFunction() {}
+TabsDiscardFunction::~TabsDiscardFunction() {}
+
 }  // namespace extensions