Update task_manager tests to handle same-site BrowsingInstance swap

With crrev.com/c/2121522, some main-frame same-site navigations will
result in a new BrowsingInstance, SiteInstance, RenderFrameHost,
RenderView, etc. This CL updates expectations of task_manager tests
that didn't expect a change of RenderFrameHosts etc. on same-site
navigations.

This CL does not include:
- Fixes for other tests in chrome/ content/, components/, and layout
tests (they're fixed in other CLs)

For more details, see doc: https://docs.google.com/document/d/1lHdkKLUe8H6ZP6ALwj-dsus7oYcuc93HkSCHCcerItg/edit?usp=sharing

Bug: 977562

Change-Id: I2066c4e6a96b984a899dcd0f977d2227d8c4c452
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2196105
Commit-Queue: Rakina Zata Amni <rakina@chromium.org>
Reviewed-by: Ahmed Fakhry <afakhry@chromium.org>
Cr-Commit-Position: refs/heads/master@{#775043}

chrome/browser/task_manager/providers/web_contents/devtools_tag_browsertest.cc

@@ -11,6 +11,7 @@
 #include "chrome/test/base/in_process_browser_test.h"
 #include "chrome/test/base/ui_test_utils.h"
 #include "content/public/test/browser_test.h"
+#include "content/public/test/test_utils.h"
 #include "net/test/embedded_test_server/embedded_test_server.h"
 
 namespace task_manager {
@@ -111,8 +112,19 @@ IN_PROC_BROWSER_TEST_F(DevToolsTagTest, DevToolsTaskIsProvided) {
   const int64_t task_id = task->task_id();
   LoadTestPage(kTestPage2);
   EXPECT_EQ(2U, tags_manager()->tracked_tags().size());
+  if (content::CanSameSiteMainFrameNavigationsChangeRenderFrameHosts()) {
+    // When ProactivelySwapBrowsingInstance or RenderDocument is enabled on
+    // same-site main frame navigations, the navigation above will result in a
+    // new RenderFrameHost, so the DevTools task will move (but still exist
+    // in the tasks list).
+    EXPECT_NE(task_id, task_manager.tasks().back()->task_id());
+    EXPECT_NE(task, task_manager.tasks().back());
+    EXPECT_EQ(task_id, task_manager.tasks()[0]->task_id());
+    EXPECT_EQ(task, task_manager.tasks()[0]);
+  } else {
     EXPECT_EQ(task_id, task_manager.tasks().back()->task_id());
     EXPECT_EQ(task, task_manager.tasks().back());
+  }
   EXPECT_NE(task_manager.tasks()[0]->title(),
             task_manager.tasks()[1]->title());
 

chrome/browser/task_manager/providers/web_contents/tab_contents_tag_browsertest.cc

@@ -23,6 +23,7 @@
 #include "content/public/browser/favicon_status.h"
 #include "content/public/browser/navigation_entry.h"
 #include "content/public/test/browser_test.h"
+#include "content/public/test/test_utils.h"
 #include "net/test/embedded_test_server/embedded_test_server.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/page_transition_types.h"
@@ -313,6 +314,14 @@ IN_PROC_BROWSER_TEST_F(TabContentsTagTest, NavigateToPageNoFavicon) {
   // Navigate to a page without a favicon.
   GURL no_favicon_page_url = GetUrlOfFile("/title1.html");
   ui_test_utils::NavigateToURL(browser(), no_favicon_page_url);
+
+  if (content::CanSameSiteMainFrameNavigationsChangeRenderFrameHosts()) {
+    // When ProactivelySwapBrowsingInstance or RenderDocument is enabled on
+    // same-site main frame navigations, we'll get a new task because we are
+    // changing RenderFrameHosts.
+    ASSERT_EQ(1U, task_manager.tasks().size());
+    task = task_manager.tasks().back();
+  }
   ASSERT_EQ(GetDefaultTitleForUrl(no_favicon_page_url), task->title());
 
   // Check that the task manager uses the default favicon for the page.