Remove confirmation dialog from BackgroundModeManager.

After UI review, we decided we don't want to display a confirmation dialog if the user turns off "Let chrome run in the background" when there are no windows open. We'll just silently exit.

BUG=76828
TEST=Install background app, close all browser windows, right click status icon and uncheck "Let chrome run...", should see no confirmation dialog.

Review URL: http://codereview.chromium.org/7064009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@86376 0039d316-1c4b-4281-b951-d872f2087c98

chrome/app/chromium_strings.grd

@@ -357,9 +357,6 @@ be available for now. -->
       <message name="IDS_OPTIONS_BACKGROUND_ENABLE_BACKGROUND_MODE" desc="The label of the check-box that enables background mode">
         Continue running background apps when Chromium is closed
       </message>
-      <message name="IDS_CONFIRM_EXIT_BACKGROUND_MODE_BODY" desc="Confirmation displayed when disabling background mode via the status tray context menu when there are no windows open">
-        Are you sure you want to quit Chromium? (This setting can be toggled in <ph name="ADVANCED_OPTIONS_TAB_TITLE">$1<ex>Options - Under the Hood</ex></ph>)
-      </message>
       <message name="IDS_CANT_WRITE_USER_DIRECTORY_SUMMARY" desc="Summary of problem displayed in dialog when we can't create a directory for this user.">
         Chromium cannot read and write to its data directory:\n\n<ph name="USER_DATA_DIRECTORY">$1<ex>C:\Documents and Settings\devint\Local Settings\Application Data\Google\Chrome</ex></ph>
       </message>

chrome/app/google_chrome_strings.grd

@@ -355,9 +355,6 @@ Chrome supports. -->
       <message name="IDS_OPTIONS_BACKGROUND_ENABLE_BACKGROUND_MODE" desc="The label of the check-box that enables background mode">
         Continue running background apps when Google Chrome is closed
       </message>
-      <message name="IDS_CONFIRM_EXIT_BACKGROUND_MODE_BODY" desc="Confirmation displayed when disabling background mode via the status tray context menu when there are no windows open">
-        Are you sure you want to quit Google Chrome? (This setting can be toggled in <ph name="ADVANCED_OPTIONS_TAB_TITLE">$1<ex>Options - Under the Hood</ex></ph>)
-      </message>
       <message name="IDS_CANT_WRITE_USER_DIRECTORY_SUMMARY" desc="Summary of problem displayed in dialog when we can't create a directory for this user.">
         Google Chrome cannot read and write to its data directory:\n\n<ph name="USER_DATA_DIRECTORY">$1<ex>C:\Documents and Settings\devint\Local Settings\Application Data\Google\Chrome</ex></ph>
       </message>

chrome/browser/background_mode_manager.cc

@@ -13,7 +13,6 @@
 #include "chrome/browser/background_mode_manager.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/extensions/extension_service.h"
-#include "chrome/browser/platform_util.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/status_icons/status_icon.h"
 #include "chrome/browser/status_icons/status_tray.h"
@@ -396,22 +395,6 @@ void BackgroundModeManager::ExecuteCommand(int item) {
       // not be visible).
       DCHECK(IsBackgroundModePrefEnabled());
       DCHECK(BrowserList::WillKeepAlive());
-      if (BrowserList::size() == 0) {
-        // There are no windows open - unchecking this will exit Chrome. Warn
-        // the user.
-        string16 tab_title = l10n_util::GetStringFUTF16(IDS_OPTIONS_TAB_TITLE,
-            l10n_util::GetStringUTF16(IDS_SETTINGS_TITLE),
-            l10n_util::GetStringUTF16(IDS_OPTIONS_ADVANCED_TAB_LABEL));
-
-        if (!platform_util::SimpleYesNoBox(
-                NULL,
-                l10n_util::GetStringUTF16(IDS_PRODUCT_NAME),
-                l10n_util::GetStringFUTF16(
-                    IDS_CONFIRM_EXIT_BACKGROUND_MODE_BODY,
-                    tab_title))) {
-          return;
-        }
-      }
 
       // Set the background mode pref to "disabled" - the resulting notification
       // will result in a call to DisableBackgroundMode().