Base for Ash browser_tests on Win8.

chrome/browser/browser_process_platform_part_aurawin.cc

 // Copyright (c) 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 "chrome/browser/browser_process_platform_part_aurawin.h"
 
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/process_util.h"
 #include "base/win/windows_version.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/metro_viewer/chrome_metro_viewer_process_host_aurawin.h"
 #include "chrome/common/chrome_switches.h"
+#include "win8/test/test_registrar_constants.h"
 
 BrowserProcessPlatformPart::BrowserProcessPlatformPart() {
 }
 
 BrowserProcessPlatformPart::~BrowserProcessPlatformPart() {
 }
 
 void BrowserProcessPlatformPart::OnMetroViewerProcessTerminated() {
   metro_viewer_process_host_.reset(NULL);
 }
 
 void BrowserProcessPlatformPart::PlatformSpecificCommandLineProcessing(
     const CommandLine& command_line) {
-  if (base::win::GetVersion() >= base::win::VERSION_WIN8 &&
-      command_line.HasSwitch(switches::kViewerConnection) &&
-      !metro_viewer_process_host_.get()) {
-    // Tell the metro viewer process host to connect to the given IPC channel.
-    metro_viewer_process_host_.reset(
-        new ChromeMetroViewerProcessHost(
-            command_line.GetSwitchValueASCII(switches::kViewerConnection)));
+  // Check for Windows 8 specific commandlines requesting that this process
+  // either connect to an existing viewer or launch a new viewer and
+  // synchronously wait for it to connect.
+  if (base::win::GetVersion() >= base::win::VERSION_WIN8) {
+    if (command_line.HasSwitch(switches::kViewerConnection) &&
+        !metro_viewer_process_host_.get()) {
+      // Tell the metro viewer process host to connect to the given IPC channel.
+      metro_viewer_process_host_.reset(
+          new ChromeMetroViewerProcessHost(
+              command_line.GetSwitchValueASCII(switches::kViewerConnection)));
+    } else if (command_line.HasSwitch(switches::kAshBrowserTests)) {

[grt (UTC plus 2), 2013/05/29 02:22:51]

i'm a little uncomfortable with this test-only code being in the product. is
there precedent for this? i guess it's a bit similar to kTestingChannelID. hmm.
please have one of the reviewers in chrome/OWNERS weigh in.

[gab, 2013/05/29 14:52:20]

Ya, I agree that this is ugly, especially that I also have to make this target
depend on test_registrar_constants (incidentally this week's edition of TotT
talks about avoiding exactly this!)...

How about I add a generic switch to the chrome switches (e.g.
kViewerLaunchViaAppId) which would only be set by browser tests for now when
they find the kAshBrowserTests switch (which could then be a test-only switch
instead of being in chrome_switches)?

A bit more involved, but it feels cleaner, WDYT?

[grt (UTC plus 2), 2013/05/29 15:51:03]

If I understand, yeah, this seems better. For what it's worth, I just became
aware of kTestCompositor, which lives along with the regular content switches,
so I see that there is precedent for putting handling of test-only switches in
the product. This makes me feel better.

[gab, 2013/05/29 23:09:42]

Okay, did that in patch set 6, let me know if you like it.

I don't like checking success with a CHECK() now that this is no longer
"test-only" code though... any better idea?

At least chrome code no longer depends on a test target...

Still having trouble linking though since weirdly enough
test/base/test_switches.cc is linked into 'browser' not 'test_support_common'
where test/base/in_process_browser_test.cc is linked into...

+      metro_viewer_process_host_.reset(
+          new ChromeMetroViewerProcessHost("viewer"));
+      CHECK(metro_viewer_process_host_->LaunchViewerAndWaitForConnection(
+          win8::test::kDefaultTestAppUserModelId));
+    }
   }
 }
 
 void BrowserProcessPlatformPart::AttemptExit() {
   // On WinAura, the regular exit path is fine except on Win8+, where Ash might
   // be active in Metro and won't go away even if all browsers are closed. The
   // viewer process, whose host holds a reference to g_browser_process, needs to
   // be killed as well.
   BrowserProcessPlatformPartBase::AttemptExit();
 
   if (base::win::GetVersion() >= base::win::VERSION_WIN8 &&
       metro_viewer_process_host_) {
     base::ProcessId viewer_id =
         metro_viewer_process_host_->GetViewerProcessId();
     if (viewer_id == base::kNullProcessId)
       return;
     // The viewer doesn't hold any state so it is fine to kill it before it
     // cleanly exits. This will trigger MetroViewerProcessHost::OnChannelError()
     // which will cleanup references to g_browser_process.
     bool success = base::KillProcessById(viewer_id, 0, true);
     DCHECK(success);
   }
 }