Prevent imbalanced keepalive counts in ProcessManager

chrome/browser/extensions/process_manager_browsertest.cc

 // Copyright 2013 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 "extensions/browser/process_manager.h"
 
 #include "chrome/browser/extensions/browser_action_test_util.h"
 #include "chrome/browser/extensions/extension_browsertest.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
@@ skipping 139 matching lines @@
   content::WebContents* extension_web_contents =
       content::WebContents::FromRenderFrameHost(
           *pm->GetRenderFrameHostsForExtension(extension->id()).begin());
   EXPECT_TRUE(extension_web_contents->GetSiteInstance() !=
               tab_web_contents->GetSiteInstance());
   EXPECT_TRUE(pm->GetSiteInstanceForURL(extension->url()) !=
               tab_web_contents->GetSiteInstance());
   EXPECT_TRUE(pm->GetBackgroundHostForExtension(extension->id()));
 }
 
+// Verify correct keepalive count behavior on network request events.
+IN_PROC_BROWSER_TEST_F(ProcessManagerBrowserTest, KeepaliveOnNetworkRequest) {
+  // Load an extension with a lazy background page.
+  scoped_refptr<const Extension> extension =
+      LoadExtension(test_data_dir_.AppendASCII("api_test")
+                        .AppendASCII("lazy_background_page")
+                        .AppendASCII("broadcast_event"));
+  ASSERT_TRUE(extension.get());
+
+  ProcessManager* pm = ProcessManager::Get(profile());
+  ProcessManager::FrameSet frames =
+      pm->GetRenderFrameHostsForExtension(extension->id());
+  EXPECT_EQ(1u, frames.size());

[Devlin, 2015/09/28 21:51:48]

nitty nit: may as well make this an assert, since you dereference [0] on line
183.

[Ken Rockot(use gerrit already), 2015/09/28 21:55:20]

Done.

+
+  // Keepalive count at this point is unpredictable as there may be an
+  // outstanding event dispatch. We use the current keepalive count as a
+  // reliable baseline for future expectations.
+  int baseline_keepalive = pm->GetLazyKeepaliveCount(extension.get());
+
+  // Simulate some network events. This test assumes no other network requests
+  // are pending, i.e., that there are no conflicts with the fake request IDs
+  // we're using. This should be a safe assumption because LoadExtension should
+  // wait for loads to complete, and we don't run the message loop otherwise.
+  content::RenderFrameHost* frame_host = *frames.begin();
+  pm->OnNetworkRequestStarted(frame_host, 1);
+  EXPECT_EQ(baseline_keepalive + 1, pm->GetLazyKeepaliveCount(extension.get()));
+  pm->OnNetworkRequestDone(frame_host, 1);
+  EXPECT_EQ(baseline_keepalive, pm->GetLazyKeepaliveCount(extension.get()));
+
+  // Simulate only a request completion for this ID and ensure it doesn't result
+  // in keepalive decrement.

[Devlin, 2015/09/28 21:51:48]

nit: add
// Regression test for crbug.com/535716.

[Ken Rockot(use gerrit already), 2015/09/28 21:55:20]

Done.

+  pm->OnNetworkRequestDone(frame_host, 2);
+  EXPECT_EQ(baseline_keepalive, pm->GetLazyKeepaliveCount(extension.get()));
+}
+
 }  // namespace extensions