Fix Android strict-mode violation in GeoLocation info bar.

chrome/browser/geolocation/chrome_geolocation_permission_context_android.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/browser/geolocation/chrome_geolocation_permission_context_android.h"
 
 #include "base/prefs/pref_service.h"
 #include "chrome/browser/android/google_location_settings_helper.h"
+#include "chrome/browser/content_settings/permission_request_id.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/pref_names.h"
 #include "content/public/browser/browser_thread.h"
 
 ChromeGeolocationPermissionContextAndroid::
     ChromeGeolocationPermissionContextAndroid(Profile* profile)
     : ChromeGeolocationPermissionContext(profile),
       google_location_settings_helper_(
           GoogleLocationSettingsHelper::Create()) {
 }
 
 ChromeGeolocationPermissionContextAndroid::
     ~ChromeGeolocationPermissionContextAndroid() {
 }
 
+void ChromeGeolocationPermissionContextAndroid::ProceedDecidePermission(
+    const PermissionRequestID& id,
+    const GURL& requesting_frame,
+    const GURL& embedder,
+    base::Callback<void(bool)> callback) {
+  // Super class implementation expects everything in UI thread instead.
+  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
+  ChromeGeolocationPermissionContext::DecidePermission(
+      id, requesting_frame, embedder, callback);
+}
+
+void ChromeGeolocationPermissionContextAndroid::CheckMasterLocation(
+    const PermissionRequestID& id,
+    const GURL& requesting_frame,
+    const GURL& embedder,
+    base::Callback<void(bool)> callback) {
+  // Check to see if the feature in its entirety has been disabled.
+  // This must happen before other services (e.g. tabs, extensions)
+  // get an opportunity to allow the geolocation request.
+  bool enabled =
+      google_location_settings_helper_->IsMasterLocationSettingEnabled();

[bulach, 2014/01/15 16:22:07]

I think my previous comment was that we could also check it here for:

"is_allow_label = google_location_settings_helper_->IsAllowLabel();" and 
google_location_settings_helper_>GetAcceptButtonLabel(is_allow_label_)

then pass to the ui_closure and then pass it all the way down to the infobar... 
that would remove the changes to infobar_delegate, that object should be just on
the UI thread, and any tasks / orchestration should be done before that object
is created...

wdyt?

+
+  // The flow for geolocation permission on android is:
+  // - ChromeGeolocationPermissionContextAndroid::DecidePermission
+  // intercepts the flow in the UI thread, and posts task
+  // to the blocking pool to CheckMasterLocation (in order to
+  // avoid strict-mode violation).
+  // - At this point the master location permission is either:
+  // -- enabled, in which we case it proceeds the normal flow
+  // via ChromeGeolocationPermissionContext (which may create infobars, etc.).
+  // -- disabled, in which case the permission is already decided.
+  //
+  // In either case, ChromeGeolocationPermissionContext expects these
+  // in the UI thread.
+  base::Closure ui_closure;
+  if (enabled) {
+    ui_closure = base::Bind(
+        &ChromeGeolocationPermissionContextAndroid::ProceedDecidePermission,
+        base::Unretained(this), id, requesting_frame, embedder, callback);
+  } else {
+    ui_closure = base::Bind(
+        &ChromeGeolocationPermissionContextAndroid::PermissionDecided,
+        base::Unretained(this), id,
+        requesting_frame, embedder, callback, false);
+  }
+
+  // This method is executed from the BlockingPool, post the result
+  // back to the UI thread.
+  content::BrowserThread::PostTask(
+      content::BrowserThread::UI, FROM_HERE, ui_closure);
+}
+
 void ChromeGeolocationPermissionContextAndroid::DecidePermission(
     const PermissionRequestID& id,
     const GURL& requesting_frame,
     const GURL& embedder,
     base::Callback<void(bool)> callback) {
+
+  // Called on the UI thread. However, do the work on a separate thread
+  // to avoid strict mode violation.
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
-
-  // Check to see if the feature in its entirety has been disabled.
-  // This must happen before other services (e.g. tabs, extensions)
-  // get an opportunity to allow the geolocation request.
-  if (!google_location_settings_helper_->IsMasterLocationSettingEnabled()) {
-    PermissionDecided(id, requesting_frame, embedder, callback, false);
-    return;
-  }
-
-  ChromeGeolocationPermissionContext::DecidePermission(id, requesting_frame,
-                                                       embedder, callback);
+  content::BrowserThread::PostBlockingPoolTask(FROM_HERE,
+      base::Bind(
+          &ChromeGeolocationPermissionContextAndroid::CheckMasterLocation,
+          base::Unretained(this), id, requesting_frame, embedder, callback));
 }
 
 void ChromeGeolocationPermissionContextAndroid::PermissionDecided(
     const PermissionRequestID& id,
     const GURL& requesting_frame,
     const GURL& embedder,
     base::Callback<void(bool)> callback,
     bool allowed) {
-  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
   // If Google Apps Location setting is turned off then we ignore
   // the 'allow' website setting for this site and instead show
   // the infobar to go back to the 'settings' to turn it back on.
   if (allowed &&
       !google_location_settings_helper_->IsGoogleAppsLocationSettingEnabled()) {
     QueueController()->CreateInfoBarRequest(id, requesting_frame, embedder,
                                             callback);
     return;
   }
 
   ChromeGeolocationPermissionContext::PermissionDecided(
       id, requesting_frame, embedder, callback, allowed);
 }