Ensure RenderViewHost is not shut down until a screenshot of the page is taken.

chrome/browser/renderer_host/render_process_host_chrome_browsertest.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 "base/command_line.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/devtools/devtools_window.h"
 #include "chrome/browser/search/search.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_commands.h"
 #include "chrome/browser/ui/singleton_tabs.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/url_constants.h"
 #include "chrome/test/base/in_process_browser_test.h"
 #include "chrome/test/base/test_switches.h"
 #include "chrome/test/base/ui_test_utils.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/render_process_host.h"
+#include "content/public/browser/render_process_host_observer.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/render_widget_host_iterator.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/browser/web_contents_observer.h"
 
 using content::RenderViewHost;
 using content::RenderWidgetHost;
 using content::WebContents;
 
 namespace {
 
+class RenderProcessHostAliveObserver

[nasko, 2014/03/26 22:48:27]

Why create a new class? Doesn't RenderProcessHostWatcher work in this case?
https://code.google.com/p/chromium/codesearch#chromium/src/content/public/tes...

[mfomitchev, 2014/03/27 21:51:34]

Done.

+    : public content::RenderProcessHostObserver {
+ public:
+  explicit RenderProcessHostAliveObserver(content::RenderProcessHost* host)
+      : host_(host) {
+    host_->AddObserver(this);
+  }
+
+  virtual ~RenderProcessHostAliveObserver() {
+    CHECK(!host_);
+  }
+
+  void WaitUntilProcessDies() {
+    if (!host_)
+      return;
+    base::RunLoop run_loop;
+    quit_closure_ = run_loop.QuitClosure();
+    run_loop.Run();
+  }
+
+ private:
+  // content::RenderProcessHostObserver:
+  virtual void RenderProcessHostDestroyed(
+      content::RenderProcessHost* host) OVERRIDE {
+    CHECK_EQ(host_, host);
+    host_ = NULL;
+    if (!quit_closure_.is_null())
+      quit_closure_.Run();
+  }
+
+  content::RenderProcessHost* host_;
+  base::Closure quit_closure_;
+
+  DISALLOW_COPY_AND_ASSIGN(RenderProcessHostAliveObserver);
+};
+
 int RenderProcessHostCount() {
   content::RenderProcessHost::iterator hosts =
       content::RenderProcessHost::AllHostsIterator();
   int count = 0;
   while (!hosts.IsAtEnd()) {
     if (hosts.GetCurrentValue()->HasConnection())
       count++;
     hosts.Advance();
   }
   return count;
@@ skipping 63 matching lines @@
   // in a process of that type, even if that means creating a new process.
   void TestProcessOverflow() {
     int tab_count = 1;
     int host_count = 1;
     WebContents* tab1 = NULL;
     WebContents* tab2 = NULL;
     content::RenderProcessHost* rph1 = NULL;
     content::RenderProcessHost* rph2 = NULL;
     content::RenderProcessHost* rph3 = NULL;
 
-    // Change the first tab to be the omnibox page (TYPE_WEBUI).
+    EXPECT_EQ(host_count, RenderProcessHostCount());
+    ASSERT_EQ(tab_count, browser()->tab_strip_model()->count());
+
+    tab1 = browser()->tab_strip_model()->GetWebContentsAt(tab_count - 1);
+    RenderProcessHostAliveObserver process_observer(
+        tab1->GetRenderProcessHost());
+
+    // Change the first tab to be the omnibox page (TYPE_WEBUI). The navigation
+    // should terminate the existing process.
     GURL omnibox(chrome::kChromeUIOmniboxURL);
     ui_test_utils::NavigateToURL(browser(), omnibox);
+    process_observer.WaitUntilProcessDies();

[nasko, 2014/03/26 22:48:27]

Please add a comment why we need to wait for the process to go away and not just
navigation.

[mfomitchev, 2014/03/27 21:51:34]

Done.

     EXPECT_EQ(tab_count, browser()->tab_strip_model()->count());
     tab1 = browser()->tab_strip_model()->GetWebContentsAt(tab_count - 1);
     rph1 = tab1->GetRenderProcessHost();
     EXPECT_EQ(omnibox, tab1->GetURL());
     EXPECT_EQ(host_count, RenderProcessHostCount());
 
     // Create a new TYPE_TABBED tab.  It should be in its own process.
     GURL page1("data:text/html,hello world1");
 
     ui_test_utils::WindowedTabAddedNotificationObserver observer1(
@@ skipping 70 matching lines @@
 IN_PROC_BROWSER_TEST_F(ChromeRenderProcessHostTest, ProcessPerTab) {
   // Set max renderers to 1 to force running out of processes.
   content::RenderProcessHost::SetMaxRendererProcessCount(1);
 
   CommandLine& parsed_command_line = *CommandLine::ForCurrentProcess();
   parsed_command_line.AppendSwitch(switches::kProcessPerTab);
 
   int tab_count = 1;
   int host_count = 1;
 
+  EXPECT_EQ(tab_count, browser()->tab_strip_model()->count());
+  EXPECT_EQ(host_count, RenderProcessHostCount());
+
+  WebContents* tab1 =
+      browser()->tab_strip_model()->GetWebContentsAt(tab_count - 1);
+  RenderProcessHostAliveObserver process_observer(tab1->GetRenderProcessHost());
+
   // Change the first tab to be the new tab page (TYPE_WEBUI).
   GURL omnibox(chrome::kChromeUIOmniboxURL);
   ui_test_utils::NavigateToURL(browser(), omnibox);
+  process_observer.WaitUntilProcessDies();

[nasko, 2014/03/26 22:48:27]

ditto on comment.

[mfomitchev, 2014/03/27 21:51:34]

Done.

   EXPECT_EQ(tab_count, browser()->tab_strip_model()->count());
   EXPECT_EQ(host_count, RenderProcessHostCount());
 
   // Create a new TYPE_TABBED tab.  It should be in its own process.
   GURL page1("data:text/html,hello world1");
   ui_test_utils::WindowedTabAddedNotificationObserver observer1(
       content::NotificationService::AllSources());
   chrome::ShowSingletonTab(browser(), page1);
   observer1.Wait();
   tab_count++;
@@ skipping 249 matching lines @@
       chrome::NOTIFICATION_BROWSER_CLOSED,
       content::NotificationService::AllSources());
 
   // Kill the renderer process, simulating a crash. This should the ProcessDied
   // method to be called. Alternatively, RenderProcessHost::OnChannelError can
   // be called to directly force a call to ProcessDied.
   base::KillProcess(wc1->GetRenderProcessHost()->GetHandle(), -1, true);
 
   observer.Wait();
 }