Clean up some VrShell threading issues and remove unnecessary WeakPtr types.

device/vr/android/gvr/gvr_gamepad_data_fetcher.cc

Index: device/vr/android/gvr/gvr_gamepad_data_fetcher.cc
diff --git a/device/vr/android/gvr/gvr_gamepad_data_fetcher.cc b/device/vr/android/gvr/gvr_gamepad_data_fetcher.cc
index 9f7f391952872f3472d577d5d46c67a675fc94a6..348beefcad523279d8ceca6272dbfb142a7279a4 100644
--- a/device/vr/android/gvr/gvr_gamepad_data_fetcher.cc
+++ b/device/vr/android/gvr/gvr_gamepad_data_fetcher.cc
@@ -28,9 +28,8 @@ void CopyToWebUString(blink::WebUChar* dest,
 
 using namespace blink;
 
-GvrGamepadDataFetcher::Factory::Factory(
-    const base::WeakPtr<GvrDelegate>& delegate,
-    unsigned int display_id)
+GvrGamepadDataFetcher::Factory::Factory(GvrDelegate* delegate,
+                                        unsigned int display_id)
     : delegate_(delegate), display_id_(display_id) {}
 
 GvrGamepadDataFetcher::Factory::~Factory() {}
@@ -39,7 +38,7 @@ std::unique_ptr<GamepadDataFetcher>
 GvrGamepadDataFetcher::Factory::CreateDataFetcher() {
   if (!delegate_)
     return nullptr;
-  return base::MakeUnique<GvrGamepadDataFetcher>(delegate_.get(), display_id_);
+  return base::MakeUnique<GvrGamepadDataFetcher>(delegate_, display_id_);
 }
 
 GamepadSource GvrGamepadDataFetcher::Factory::source() {