Some more improvements/fixes to the VulkanViewer

* display GM name in title bar
* add ms timer for update loop
* add ms/frame meter
* fix vsync
* add some notes for later

GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1873453002

Review URL: https://codereview.chromium.org/1873453002
diff --git a/tools/vulkan/Window.cpp b/tools/vulkan/Window.cpp
index 86f1814..2741f4d 100644
--- a/tools/vulkan/Window.cpp
+++ b/tools/vulkan/Window.cpp
@@ -61,6 +61,8 @@
         canvas->flush();
 
         fTestContext->swapBuffers();
+    } else {
+        // try recreating testcontext
     }
 
 }