Make application shortcuts point to app_host.exe, install App Host during app installation.

chrome/browser/extensions/crx_installer.cc

Index: chrome/browser/extensions/crx_installer.cc
diff --git a/chrome/browser/extensions/crx_installer.cc b/chrome/browser/extensions/crx_installer.cc
index d1f2a77c1f21132033696985f1e761549670cf66..3b2390010bb7beb23351ca3f613fbbeb6d40cca3 100644
--- a/chrome/browser/extensions/crx_installer.cc
+++ b/chrome/browser/extensions/crx_installer.cc
@@ -21,6 +21,7 @@
 #include "base/utf_string_conversions.h"
 #include "base/version.h"
 #include "chrome/browser/browser_process.h"
+#include "chrome/browser/extensions/app_host_installer.h"
 #include "chrome/browser/extensions/convert_user_script.h"
 #include "chrome/browser/extensions/convert_web_app.h"
 #include "chrome/browser/extensions/default_apps_trial.h"
@@ -457,7 +458,7 @@ void CrxInstaller::ConfirmInstall() {
   } else {
     if (!BrowserThread::PostTask(
             BrowserThread::FILE, FROM_HERE,
-            base::Bind(&CrxInstaller::CompleteInstall, this)))
+            base::Bind(&CrxInstaller::BeginInstall, this)))
       NOTREACHED();
   }
   return;
@@ -466,7 +467,7 @@ void CrxInstaller::ConfirmInstall() {
 void CrxInstaller::InstallUIProceed() {
   if (!BrowserThread::PostTask(
           BrowserThread::FILE, FROM_HERE,
-          base::Bind(&CrxInstaller::CompleteInstall, this)))
+          base::Bind(&CrxInstaller::BeginInstall, this)))
     NOTREACHED();
 
   Release();  // balanced in ConfirmInstall().
@@ -494,7 +495,7 @@ void CrxInstaller::InstallUIAbort(bool user_initiated) {
   // should go to zero and we die. The destructor will clean up the temp dir.
 }
 
-void CrxInstaller::CompleteInstall() {
+void CrxInstaller::BeginInstall() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
 
   if (!current_version_.empty()) {
@@ -508,6 +509,26 @@ void CrxInstaller::CompleteInstall() {
       return;
     }
   }
+  if (AppHostInstaller::IsAppHostInstallRequired(*extension_)) {
+    app_host_installer_.InstallAppHost(
+        base::Bind(&CrxInstaller::OnAppHostInstallation, this));

[benwells, 2012/10/04 07:53:01]

early return here and remove the else

[huangs, 2012/10/04 22:56:42]

Done.

+  } else {
+    CompleteInstall();
+  }
+}
+
+void CrxInstaller::OnAppHostInstallation(bool success) {

[erikwright (departed), 2012/10/04 01:28:16]

OnAppHostInstallationComplete

[huangs, 2012/10/04 22:56:42]

Done.

+  if (success) {
+    CompleteInstall();

[benwells, 2012/10/04 07:53:01]

Early return and remove the else

[huangs, 2012/10/04 22:56:42]

Done.

+  } else {
+    // TODO(huangs): Error message.

[benwells, 2012/10/04 07:53:01]

I take it you'll remove this TODO / fix the error before committing?

[huangs, 2012/10/04 22:56:42]

Done.

+    string16 error = L"Some random error message";
+    ReportFailureFromFileThread(CrxInstallerError(error));
+  }
+}
+
+void CrxInstaller::CompleteInstall() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
 
   // See how long extension install paths are.  This is important on
   // windows, because file operations may fail if the path to a file