mustash chrome: Change how mus connection is set up in chrome.

chrome/browser/chrome_content_browser_client.cc

Index: chrome/browser/chrome_content_browser_client.cc
diff --git a/chrome/browser/chrome_content_browser_client.cc b/chrome/browser/chrome_content_browser_client.cc
index 4f0bf8e06a13e0812c4e0735fdfa0a73d1440560..86e97c4a1afe38a1b051110199bc2f93928be07e 100644
--- a/chrome/browser/chrome_content_browser_client.cc
+++ b/chrome/browser/chrome_content_browser_client.cc
@@ -246,6 +246,13 @@
 #include "chrome/browser/ui/views/chrome_browser_main_extra_parts_views_linux.h"
 #endif
 
+#if defined(USE_AURA)
+#include "base/run_loop.h"
+#include "content/public/common/mojo_shell_connection.h"
+#include "services/shell/runner/common/client_util.h"
+#include "ui/views/mus/window_manager_connection.h"
+#endif
+
 #if defined(USE_ASH)
 #include "chrome/browser/ui/views/ash/chrome_browser_main_extra_parts_ash.h"
 #endif
@@ -767,6 +774,10 @@ ChromeContentBrowserClient::ChromeContentBrowserClient()
 }
 
 ChromeContentBrowserClient::~ChromeContentBrowserClient() {
+  // Attempting to destroy the WindowManagerConnection here results in a crash,
+  // since the thread is shutting down and the AtExitManager is running the tear
+  // down callbacks. So let it leak.
+  window_manager_connection_.release();
   for (int i = static_cast<int>(extra_parts_.size()) - 1; i >= 0; --i)
     delete extra_parts_[i];
   extra_parts_.clear();
@@ -2857,6 +2868,19 @@ void ChromeContentBrowserClient::RegisterOutOfProcessMojoApplications(
   apps->insert(std::make_pair("mojo:media",
                               base::ASCIIToUTF16("Media App")));
 #endif
+#if defined(USE_AURA)

[Ben Goodger (Google), 2016/08/05 23:01:21]

this seems like a really arbitrary place to do this initialization.

what was the objection to having the specific method?

fwiw, I have it on my list to figure out a more generic way of expressing what
this method is actually designed for.

[jam, 2016/08/05 23:07:07]

I was asking Sadrul if there are ways of doing this without adding extra
embedder callbacks from content. Given that we're trying to reduce content,
having more intertwining seemed going in the other direction.

btw we could keep this code in chrome_browser_main_extra_parts_views still right
Sadurl? Perhaps just add RegisterOutOfProcessMojoApplications to
ChromeBrowserMainExtraParts

[sadrul, 2016/08/05 23:24:39]

ChromeContentBrowserClient does create ChromeBrowserMainExtraPartsViews, but it
passes ownership of that to content::BrowserMainLoop, and doesn't retain any
reference to it. Keeping the WindowManagerConnection in the *ExtraPartsView, and
triggering RegisterOutOfProcessMojoApplications() on the *MainExtraParts from
here would be possible, but would not be very clean. (ChromeContentBrowserClient
here would need to retain a raw pointer to the ChromeBrowserMainParts it creates
in CreateBrowserMainParts() above, expose the *ExtraParts from
ChromeBrowserMainParts and trigger the callback on them here (or add to the
ChromeBrowserMainParts API to trigger the callback on the extra parts). This
also makes the assumption (and a reasonably safe one, I suppose) that the
ChromeBrowserMainParts object it created is still alive when we reach here.

+  if (shell::ShellIsRemote()) {
+    content::MojoShellConnection* connection =
+        content::MojoShellConnection::GetForProcess();
+    // TODO(rockot): Remove the blocking wait for init.
+    // http://crbug.com/594852.
+    base::RunLoop wait_loop;
+    connection->SetInitializeHandler(wait_loop.QuitClosure());
+    wait_loop.Run();
+    window_manager_connection_ = views::WindowManagerConnection::Create(
+        connection->GetConnector(), connection->GetIdentity());
+  }
+#endif
 }
 
 void ChromeContentBrowserClient::OpenURL(