Add OpenGL context to Viewer.

tools/viewer/sk_app/android/Window_android.cpp

 /*
 * Copyright 2016 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */
 
 #include "Window_android.h"
 
 #include "VulkanWindowContext_android.h"
@@ skipping 23 matching lines @@
         // fWindowContext doesn't exist because we haven't
         // initDisplay yet.
         return fDisplayParams;
     }
 }
 
 void Window_android::setTitle(const char* title) {
     fSkiaAndroidApp->setTitle(title);
 }
 
-bool Window_android::attach(BackEndType attachType, const DisplayParams& params) {
+bool Window_android::attach(BackendType attachType, const DisplayParams& params) {
     if (kVulkan_BackendType != attachType) {
         return false;
     }
 
     fDisplayParams = params;
 
     // We delay the creation of fTestContext until Android informs us that
     // the native window is ready to use.
     return true;
 }
 
 void Window_android::initDisplay(ANativeWindow* window) {
     SkASSERT(window);
     ContextPlatformData_android platformData;
     platformData.fNativeWindow = window;
     fWindowContext = VulkanWindowContext::Create((void*)&platformData, fDisplayParams);
 }
 
 void Window_android::onDisplayDestroyed() {
     detach();
 }
 
 void Window_android::inval() {
     fSkiaAndroidApp->inval();
 }
 
 }   // namespace sk_app