Fetch and actually set prefs (using chrome.send for now).

chrome/browser/ui/webui/md_settings_ui.cc

Index: chrome/browser/ui/webui/md_settings_ui.cc
diff --git a/chrome/browser/ui/webui/md_settings_ui.cc b/chrome/browser/ui/webui/md_settings_ui.cc
index 4c24d7f1a275d82fb57f36fbeabfc4585cb0bd25..39f56b99b0b356b3eb60034609e55b1a8abe6670 100644
--- a/chrome/browser/ui/webui/md_settings_ui.cc
+++ b/chrome/browser/ui/webui/md_settings_ui.cc
@@ -7,6 +7,8 @@
 #include <string>
 
 #include "base/values.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/ui/webui/options/core_options_handler.h"
 #include "chrome/common/url_constants.h"
 #include "chrome/grit/generated_resources.h"
 #include "content/public/browser/web_contents.h"
@@ -16,8 +18,26 @@
 #include "grit/settings_resources.h"
 #include "grit/settings_resources_map.h"
 
+#if defined(OS_CHROMEOS)
+#include "chrome/browser/ui/webui/options/chromeos/core_chromeos_options_handler.h"
+#endif
+
 MdSettingsUI::MdSettingsUI(content::WebUI* web_ui)
     : content::WebUIController(web_ui) {
+  // TODO(jlklein): Remove handler logic once settingsPrivate is ready.
+  #if defined(OS_CHROMEOS)

[Dan Beam, 2015/03/19 23:47:09]

0-indent #ifs, e.g.

    // TODO(jlklein):
#if defined(OS_CHROMEOS)
    core_handler_ = ...;
#else
    core_handler_ = ...;
#endif

[Jeremy Klein, 2015/03/20 00:45:38]

Ah I see. Misunderstood Michael's comment here. Done.

+    core_handler_ = new chromeos::options::CoreChromeOSOptionsHandler();
+  #else
+    core_handler_ = new options::CoreOptionsHandler();
+  #endif
+
+  core_handler_->set_handlers_host(this);
+  scoped_ptr<options::OptionsPageUIHandler> handler(core_handler_);
+  DCHECK(handler.get());

[Dan Beam, 2015/03/19 23:47:09]

what are you DCHECK()ing?

[Jeremy Klein, 2015/03/20 00:45:38]

Caught me copy-pasta-ing. Looks like this isn't needed here. Got it from:

https://code.google.com/p/chromium/codesearch#chromium/src/chrome/browser/ui/...

Where it needed to verify the handler's existance/non-nullness.

+  if (handler->IsEnabled()) {

[Dan Beam, 2015/03/19 23:47:09]

no curlies

[Jeremy Klein, 2015/03/20 00:45:38]

Done.

+    web_ui->AddMessageHandler(handler.release());
+  }
+
   content::WebUIDataSource* html_source =
       content::WebUIDataSource::Create(chrome::kChromeUIMdSettingsHost);
 
@@ -36,3 +56,13 @@ MdSettingsUI::MdSettingsUI(content::WebUI* web_ui)
 
 MdSettingsUI::~MdSettingsUI() {
 }
+
+void MdSettingsUI::InitializeHandlers() {
+  Profile* profile = Profile::FromWebUI(web_ui());
+  DCHECK(!profile->IsOffTheRecord() || profile->IsGuestSession());
+
+  core_handler_->InitializeHandler();
+  core_handler_->InitializePage();
+}
+
+void MdSettingsUI::OnFinishedLoading() {}

[Dan Beam, 2015/03/19 23:47:09]

remove or explain why you're changing the behavior

[Jeremy Klein, 2015/03/20 00:45:38]

Nothin' to see here, just me bein a C++ n00b thinking I needed to override this.
Removed here and in the .h.