Fix visualbench exiting on startup on android

BUG=skia:

Review URL: https://codereview.chromium.org/1416123003
diff --git a/platform_tools/android/apps/visualbench/src/main/jni/SkOSWindow_AndroidNative.cpp b/platform_tools/android/apps/visualbench/src/main/jni/SkOSWindow_AndroidNative.cpp
index 487835b..a35742b 100644
--- a/platform_tools/android/apps/visualbench/src/main/jni/SkOSWindow_AndroidNative.cpp
+++ b/platform_tools/android/apps/visualbench/src/main/jni/SkOSWindow_AndroidNative.cpp
@@ -18,19 +18,7 @@
 }
 
 SkOSWindow::~SkOSWindow() {
-    if (fWindow.fDisplay != EGL_NO_DISPLAY) {
-        eglMakeCurrent(fWindow.fDisplay, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);
-        if (fWindow.fContext != EGL_NO_CONTEXT) {
-            eglDestroyContext(fWindow.fDisplay, fWindow.fContext);
-        }
-        if (fWindow.fSurface != EGL_NO_SURFACE) {
-            eglDestroySurface(fWindow.fDisplay, fWindow.fSurface);
-        }
-        eglTerminate(fWindow.fDisplay);
-    }
-    fWindow.fDisplay = EGL_NO_DISPLAY;
-    fWindow.fContext = EGL_NO_CONTEXT;
-    fWindow.fSurface = EGL_NO_SURFACE;
+    this->detach();
 }
 
 bool SkOSWindow::attach(SkBackEndTypes attachType,
@@ -147,7 +135,19 @@
 }
 
 void SkOSWindow::detach() {
-    fDestroyRequested = true;
+    if (fWindow.fDisplay != EGL_NO_DISPLAY) {
+        eglMakeCurrent(fWindow.fDisplay, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);
+        if (fWindow.fContext != EGL_NO_CONTEXT) {
+            eglDestroyContext(fWindow.fDisplay, fWindow.fContext);
+        }
+        if (fWindow.fSurface != EGL_NO_SURFACE) {
+            eglDestroySurface(fWindow.fDisplay, fWindow.fSurface);
+        }
+        eglTerminate(fWindow.fDisplay);
+    }
+    fWindow.fDisplay = EGL_NO_DISPLAY;
+    fWindow.fContext = EGL_NO_CONTEXT;
+    fWindow.fSurface = EGL_NO_SURFACE;
 }
 
 void SkOSWindow::present() {