Implement HeadlessContentBrowserClient::GetAcceptLangs();

This method was previously unused, but with the network service moving
out of process, the speech recognition code will now need to use it.

No idea if we use speech recognition on headless (Though it does seem
unlikely), so this may not be needed?

Bug: 841445
Change-Id: I2c75a53663f46ddfbbd14aeac4ab3d6686d7d6e0
Reviewed-on: https://chromium-review.googlesource.com/1145711Reviewed-by: Andrey Kosyakov <caseq@chromium.org>
Commit-Queue: Matt Menke <mmenke@chromium.org>
Cr-Commit-Position: refs/heads/master@{#578128}

headless/lib/browser/headless_content_browser_client.cc

@@ -277,6 +277,11 @@ void HeadlessContentBrowserClient::AppendExtraCommandLineSwitches(
   }
 }
 
+std::string HeadlessContentBrowserClient::GetAcceptLangs(
+    content::BrowserContext* context) {
+  return browser_->options()->accept_language;
+}
+
 void HeadlessContentBrowserClient::AllowCertificateError(
     content::WebContents* web_contents,
     int cert_error,

headless/lib/browser/headless_content_browser_client.h

@@ -40,7 +40,7 @@ class HeadlessContentBrowserClient : public content::ContentBrowserClient {
 #endif
   void AppendExtraCommandLineSwitches(base::CommandLine* command_line,
                                       int child_process_id) override;
-
+  std::string GetAcceptLangs(content::BrowserContext* context) override;
   void AllowCertificateError(
       content::WebContents* web_contents,
       int cert_error,
@@ -51,15 +51,12 @@ class HeadlessContentBrowserClient : public content::ContentBrowserClient {
       bool expired_previous_decision,
       const base::Callback<void(content::CertificateRequestResultType)>&
           callback) override;
-
   void SelectClientCertificate(
       content::WebContents* web_contents,
       net::SSLCertRequestInfo* cert_request_info,
       net::ClientCertIdentityList client_certs,
       std::unique_ptr<content::ClientCertificateDelegate> delegate) override;
-
   void ResourceDispatcherHostCreated() override;
-
   bool DoesSiteRequireDedicatedProcess(content::BrowserContext* browser_context,
                                        const GURL& effective_site_url) override;