Uninstall Chrome + has App Host + not App Launcher => Uninstall App Host.

chrome/installer/util/installer_state.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 "chrome/installer/util/installer_state.h"
 
 #include <algorithm>
 #include <functional>
 #include <utility>
 
@@ skipping 101 matching lines @@
 
   if (!prefs.GetBool(master_preferences::kMsi, &msi_))
     msi_ = false;
 
   ensure_google_update_present_ =
       command_line.HasSwitch(installer::switches::kEnsureGoogleUpdatePresent);
 
   const bool is_uninstall = command_line.HasSwitch(switches::kUninstall);
 
   if (prefs.install_chrome()) {
-    Product* p =
-        AddProductFromPreferences(BrowserDistribution::CHROME_BROWSER, prefs,
-                                  machine_state);
+    Product* p = AddProductFromPreferences(

[grt (UTC plus 2), 2012/11/16 21:01:46]

reformatting like this makes it more difficult to review the changes.  in
general, please don't reformat code that isn't wildly inconsistent with the
style guide unless you're touching it for other reasons.

[huangs, 2012/11/16 21:32:02]

Okay, will avoid in future.

+        BrowserDistribution::CHROME_BROWSER, prefs, machine_state);
     VLOG(1) << (is_uninstall ? "Uninstall" : "Install")
             << " distribution: " << p->distribution()->GetAppShortCutName();
   }
   if (prefs.install_chrome_frame()) {
-    Product* p =
-        AddProductFromPreferences(BrowserDistribution::CHROME_FRAME, prefs,
-                                  machine_state);
+    Product* p = AddProductFromPreferences(
+        BrowserDistribution::CHROME_FRAME, prefs, machine_state);
     VLOG(1) << (is_uninstall ? "Uninstall" : "Install")
             << " distribution: " << p->distribution()->GetAppShortCutName();
   }
+
   if (prefs.install_chrome_app_host()) {
-    Product* p =
-        AddProductFromPreferences(BrowserDistribution::CHROME_APP_HOST, prefs,
-                                  machine_state);
+    Product* p = AddProductFromPreferences(
+        BrowserDistribution::CHROME_APP_HOST, prefs, machine_state);
     VLOG(1) << (is_uninstall ? "Uninstall" : "Install")
             << " distribution: " << p->distribution()->GetAppShortCutName();
   }
 
   if (!is_uninstall && is_multi_install()) {
     bool need_binaries = false;
     if (FindProduct(BrowserDistribution::CHROME_APP_HOST)) {
       // App Host will happily use Chrome at system level, or binaries at system
       // level, even if app host is user level.
       const ProductState* chrome_state = machine_state.GetProductState(
@@ skipping 11 matching lines @@
 
     // Chrome/Chrome Frame multi need Binaries at their own level.
     if (FindProduct(BrowserDistribution::CHROME_BROWSER))
       need_binaries = true;
 
     if (FindProduct(BrowserDistribution::CHROME_FRAME))
       need_binaries = true;
 
     if (need_binaries && !FindProduct(BrowserDistribution::CHROME_BINARIES)) {
       // Force binaries to be installed/updated.
-      Product* p =
-          AddProductFromPreferences(BrowserDistribution::CHROME_BINARIES,
-                                    prefs,
-                                    machine_state);
+      Product* p = AddProductFromPreferences(
+          BrowserDistribution::CHROME_BINARIES, prefs, machine_state);
       VLOG(1) << "Install distribution: "
               << p->distribution()->GetAppShortCutName();
     }
   }
 
   if (is_uninstall && prefs.is_multi_install()) {
+    // Uninstall App Host if Chrome is being uninstalled, and (non-App Launcher)
+    // App Host exists.  If we uninstall system-level Chrome, but we have
+    // user-level (non-App Launcher) App Host, then app_host.exe remains.
+    // On next execution, app_host.exe prompts user for further action.
+    if (is_uninstall && prefs.install_chrome()

[grt (UTC plus 2), 2012/11/16 21:01:46]

- is_uninstall is tested on line 175, so please remove.
- chrome being uninstalled is tested on line 194, so don't do that again here. 
instead, put this new code inside that conditional.
- i suggest you follow the pattern here and use
FindProduct(BrowserDistribution::CHROME_APP_HOST) instead of checking prefs.

[huangs, 2012/11/16 21:32:02]

Done.

+            && !prefs.install_chrome_app_host()) {
+      const ProductState* app_host_state = machine_state.GetProductState(
+          system_install(), BrowserDistribution::CHROME_APP_HOST);
+      // If App Host (non-App Launcher) is installed.
+      if (app_host_state && !app_host_state->uninstall_command()
+              .HasSwitch(switches::kChromeAppLauncher)) {
+        Product* p = AddProductFromPreferences(
+            BrowserDistribution::CHROME_APP_HOST, prefs, machine_state);
+        VLOG(1) << "Also uninstall distribution: "
+                << p->distribution()->GetAppShortCutName();
+      }
+    }
+
     if (FindProduct(BrowserDistribution::CHROME_BROWSER)) {
       const ProductState* chrome_frame_state = machine_state.GetProductState(
           system_install(), BrowserDistribution::CHROME_FRAME);
 
       if (chrome_frame_state != NULL &&
           chrome_frame_state->uninstall_command().HasSwitch(
               switches::kChromeFrameReadyMode) &&
           !FindProduct(BrowserDistribution::CHROME_FRAME)) {
         // Chrome Frame is installed in Ready Mode. Remove it along with Chrome.
         Product* p = AddProductFromPreferences(
@@ skipping 39 matching lines @@
             keep_binaries = true;
             break;
           }
 
         }
       }
 
       // The product is being uninstalled.
     }
     if (!keep_binaries) {
-      Product* p =
-          AddProductFromPreferences(BrowserDistribution::CHROME_BINARIES, prefs,
-                                    machine_state);
+      Product* p = AddProductFromPreferences(
+          BrowserDistribution::CHROME_BINARIES, prefs, machine_state);
       VLOG(1) << (is_uninstall ? "Uninstall" : "Install")
               << " distribution: " << p->distribution()->GetAppShortCutName();
     }
   }
 
   BrowserDistribution* operand = NULL;
 
   if (is_uninstall) {
     operation_ = UNINSTALL;
   } else if (!prefs.is_multi_install()) {
@@ skipping 511 matching lines @@
   if (is_multi_install()) {
     InstallUtil::AddInstallerResultItems(
         system_install, multi_package_binaries_distribution()->GetStateKey(),
         status, string_resource_id, launch_cmd, install_list.get());
   }
   if (!install_list->Do())
     LOG(ERROR) << "Failed to record installer error information in registry.";
 }
 
 }  // namespace installer