[Part 1 of 6] Move MockWebContentsTaskManager into its own file.

chrome/browser/task_manager/task_manager_browsertest.cc

Index: chrome/browser/task_manager/task_manager_browsertest.cc
diff --git a/chrome/browser/task_manager/task_manager_browsertest.cc b/chrome/browser/task_manager/task_manager_browsertest.cc
index 3b2e26faf24f4da2562e92a462a16da2c81ea23e..0f3f17b7494e1dbeb0f3889db2d4c2266cff17f1 100644
--- a/chrome/browser/task_manager/task_manager_browsertest.cc
+++ b/chrome/browser/task_manager/task_manager_browsertest.cc
@@ -302,13 +302,10 @@ IN_PROC_BROWSER_TEST_F(TaskManagerBrowserTest, NoticePanel) {
   // Open a new panel to an extension url.
   GURL url(
     "chrome-extension://behllobkkfkfnphdnhnkndlbkcpglgmj/french_sentence.html");
-  Panel* panel = PanelManager::GetInstance()->CreatePanel(
+  Panel* docked_panel = PanelManager::GetInstance()->CreatePanel(
       web_app::GenerateApplicationNameFromExtensionId(
           last_loaded_extension_id()),
-      browser()->profile(),
-      url,
-      nullptr,
-      gfx::Rect(300, 400),
+      browser()->profile(), url, nullptr, gfx::Rect(300, 400),
       PanelManager::CREATE_AS_DOCKED);
 
   // Make sure that a task manager model created after the panel shows the
@@ -325,8 +322,30 @@ IN_PROC_BROWSER_TEST_F(TaskManagerBrowserTest, NoticePanel) {
   ASSERT_NO_FATAL_FAILURE(WaitForTaskManagerRows(1, MatchAboutBlankTab()));
   ASSERT_NO_FATAL_FAILURE(WaitForTaskManagerRows(1, MatchAnyTab()));
 
-  // Close the panel and verify that we notice.
-  panel->Close();
+  // Create a second, detached panel.
+  Panel* detached_panel = PanelManager::GetInstance()->CreatePanel(
+      web_app::GenerateApplicationNameFromExtensionId(
+          last_loaded_extension_id()),
+      browser()->profile(), url, nullptr, gfx::Rect(150, 150),
+      PanelManager::CREATE_AS_DETACHED);

[afakhry, 2016/05/06 23:52:02]

Can you also create a panel with SHOW_AS_INACTIVE? Just to make sure we didn't
lose coverage for that?

[ncarter (slow), 2016/05/09 16:43:03]

Done. I've added calls to panel->Show() / panel->ShowInactive() throughout these
tests, so we have even better coverage than before.

[afakhry, 2016/05/09 17:35:36]

Thanks!

+
+  ASSERT_NO_FATAL_FAILURE(WaitForTaskManagerRows(
+      2, MatchExtension("chrome-extension://behllobkkfkfnphdnhnkndlbkcpglgmj/"
+                        "french_sentence.html")));
+  ASSERT_NO_FATAL_FAILURE(
+      WaitForTaskManagerRows(1, MatchExtension("My extension 1")));
+  ASSERT_NO_FATAL_FAILURE(WaitForTaskManagerRows(3, MatchAnyExtension()));
+
+  // Close the panels and verify that we notice.
+  docked_panel->Close();
+  ASSERT_NO_FATAL_FAILURE(WaitForTaskManagerRows(2, MatchAnyExtension()));
+  ASSERT_NO_FATAL_FAILURE(WaitForTaskManagerRows(
+      1, MatchExtension("chrome-extension://behllobkkfkfnphdnhnkndlbkcpglgmj/"
+                        "french_sentence.html")));
+  ASSERT_NO_FATAL_FAILURE(
+      WaitForTaskManagerRows(1, MatchExtension("My extension 1")));
+
+  detached_panel->Close();
   ASSERT_NO_FATAL_FAILURE(WaitForTaskManagerRows(1, MatchAnyExtension()));
   ASSERT_NO_FATAL_FAILURE(WaitForTaskManagerRows(
       0,