[Android] Add AndroidSpellChecker feature to allow for gradual rollout using finch.

android_webview/browser/aw_content_browser_client.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 "android_webview/browser/aw_content_browser_client.h"
 
 #include <utility>
 
 #include "android_webview/browser/aw_browser_context.h"
 #include "android_webview/browser/aw_browser_main_parts.h"
@@ skipping 207 matching lines @@
   // per-view access checks, and access is granted by default (see
   // AwSettings.mAllowContentUrlAccess).
   content::ChildProcessSecurityPolicy::GetInstance()->GrantScheme(
       host->GetID(), url::kContentScheme);
 
   host->AddFilter(new AwContentsMessageFilter(host->GetID()));
   host->AddFilter(new cdm::CdmMessageFilterAndroid());
   host->AddFilter(new AwPrintingMessageFilter(host->GetID()));
 
 #if defined(ENABLE_SPELLCHECK)
-  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
-      spellcheck::switches::kEnableAndroidSpellChecker)) {

[Tobias Sargeant, 2016/08/30 10:39:52]

How does webview turn on the spellcheck feature now?

[timvolodine, 2016/08/30 13:17:42]

it's a feature now, so will be able to do something like:
--enable-features=AndroidSpellChecker

-    host->AddFilter(new SpellCheckMessageFilterPlatform(host->GetID()));
-  }
+  host->AddFilter(new SpellCheckMessageFilterPlatform(host->GetID()));
 #endif
 }
 
 bool AwContentBrowserClient::IsHandledURL(const GURL& url) {
   if (!url.is_valid()) {
     // We handle error cases.
     return true;
   }
 
   const std::string scheme = url.scheme();
@@ skipping 279 matching lines @@
 
 #if defined(VIDEO_HOLE)
 content::ExternalVideoSurfaceContainer*
 AwContentBrowserClient::OverrideCreateExternalVideoSurfaceContainer(
     content::WebContents* web_contents) {
   return native_factory_->CreateExternalVideoSurfaceContainer(web_contents);
 }
 #endif
 
 }  // namespace android_webview