[Android] Add spellchecking support in android_webview.

android_webview/renderer/aw_content_renderer_client.cc

Index: android_webview/renderer/aw_content_renderer_client.cc
diff --git a/android_webview/renderer/aw_content_renderer_client.cc b/android_webview/renderer/aw_content_renderer_client.cc
index ed4fddf7d1e2ce92710171450798fc8f5db91b10..5a7b385b6695e3b01c41e715596e3dc39348e1ab 100644
--- a/android_webview/renderer/aw_content_renderer_client.cc
+++ b/android_webview/renderer/aw_content_renderer_client.cc
@@ -52,6 +52,11 @@
 #include "url/gurl.h"
 #include "url/url_constants.h"
 
+#if defined(ENABLE_SPELLCHECK)
+#include "components/spellcheck/renderer/spellcheck.h"
+#include "components/spellcheck/renderer/spellcheck_provider.h"
+#endif
+
 using content::RenderThread;
 
 namespace android_webview {
@@ -74,6 +79,13 @@ void AwContentRendererClient::RenderThreadStarted() {
   blink::WebString aw_scheme(
       base::ASCIIToUTF16(android_webview::kAndroidWebViewVideoPosterScheme));
   blink::WebSecurityPolicy::registerURLSchemeAsSecure(aw_scheme);
+
+#if defined(ENABLE_SPELLCHECK)
+  if (!spellcheck_) {
+    spellcheck_ = base::MakeUnique<SpellCheck>();
+    thread->AddObserver(spellcheck_.get());
+  }
+#endif
 }
 
 bool AwContentRendererClient::HandleNavigation(
@@ -163,6 +175,10 @@ void AwContentRendererClient::RenderViewCreated(
   new printing::PrintWebViewHelper(
       render_view, std::unique_ptr<printing::PrintWebViewHelper::Delegate>(
                        new AwPrintWebViewHelperDelegate()));
+
+#if defined(ENABLE_SPELLCHECK)
+  new SpellCheckProvider(render_view, spellcheck_.get());
+#endif
 }
 
 bool AwContentRendererClient::HasErrorPage(int http_status_code,