Task Manager: Make double-clicking on an extension do something useful.

chrome/browser/task_management/providers/web_contents/extension_task.cc

 // Copyright 2015 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/task_management/providers/web_contents/extension_task.h"
 
 #include "base/strings/utf_string_conversions.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/ui/browser.h"
+#include "chrome/browser/ui/browser_finder.h"
+#include "chrome/browser/ui/chrome_pages.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/web_contents.h"
 #include "extensions/browser/view_type_utils.h"
 #include "extensions/common/constants.h"
 #include "extensions/common/extension.h"
 #include "extensions/common/manifest_handlers/icons_handler.h"
 #include "extensions/common/view_type.h"
 #include "grit/theme_resources.h"
 #include "ui/base/resource/resource_bundle.h"
 
@@ skipping 16 matching lines @@
 }
 
 }  // namespace
 
 ExtensionTask::ExtensionTask(content::WebContents* web_contents,
                              const extensions::Extension* extension,
                              extensions::ViewType view_type)
     : RendererTask(GetExtensionTitle(web_contents, extension, view_type),
                    GetDefaultIcon(),
                    web_contents,
-                   web_contents->GetRenderProcessHost()) {
+                   web_contents->GetRenderProcessHost()),
+      extension_id_(extension->id()) {

[afakhry, 2016/05/25 18:50:59]

I applied this locally and flashed it on a chromeos device. This causes a crash
on startup. |extension| is nullptr.

That's why in GetExtensionTitle() and LoadExtensionIcon() we always check for
|extension| not being null. You need to account for this.

[ncarter (slow), 2016/05/25 19:59:09]

Yuck. Thanks for figuring that out.

   LoadExtensionIcon(extension);
 }
 
 ExtensionTask::~ExtensionTask() {
 }
 
 void ExtensionTask::UpdateTitle() {
   // The title of the extension should not change as a result of title change
   // in its WebContents, so we ignore this.
 }
 
 void ExtensionTask::UpdateFavicon() {
   // We don't care about the favicon of the WebContents but rather of the
   // extension.
 }
 
+void ExtensionTask::Activate() {
+  // TODO(nick): For extensions::VIEW_TYPE_APP_WINDOW, and maybe others, there
+  // may actually be a window we could focus. Special case those here as needed.
+  Browser* browser = chrome::FindTabbedBrowser(
+      Profile::FromBrowserContext(web_contents()->GetBrowserContext()), true);
+
+  // If an existing browser isn't found, don't create a new one.
+  if (!browser)
+    return;
+
+  chrome::ShowExtensions(browser, extension_id_);
+}
+
 Task::Type ExtensionTask::GetType() const {
   return Task::EXTENSION;
 }
 
 void ExtensionTask::OnExtensionIconImageChanged(extensions::IconImage* image) {
   DCHECK_EQ(extension_icon_.get(), image);
 
   if (!image->image_skia().isNull())
     set_icon(image->image_skia());
 }
@@ skipping 30 matching lines @@
                                 extension_misc::EXTENSION_ICON_SMALL,
                                 icon(),
                                 this));
 
   // Triggers actual image loading with 1x resources.
   extension_icon_->image_skia().GetRepresentation(1.0f);
   set_icon(extension_icon_->image_skia());
 }
 
 }  // namespace task_management