Added --deepColor option to SampleApp, triggers creation of a ten-bit/channel buffer on Windows.

example/HelloWorld.cpp

Index: example/HelloWorld.cpp
diff --git a/example/HelloWorld.cpp b/example/HelloWorld.cpp
index 892dce1c805251a31abc956273b199872c3268b8..c2dd7d89f1b648e967bbaa92f52bb55f6899759c 100644
--- a/example/HelloWorld.cpp
+++ b/example/HelloWorld.cpp
@@ -62,7 +62,7 @@ bool HelloWorldWindow::setUpBackend() {
     this->setVisibleP(true);
     this->setClipToBounds(false);
 
-    bool result = attach(kNativeGL_BackEndType, 0 /*msaa*/, &fAttachmentInfo);
+    bool result = attach(kNativeGL_BackEndType, 0 /*msaa*/, false, &fAttachmentInfo);
     if (false == result) {
         SkDebugf("Not possible to create backend.\n");
         release();