Add text animation sample; tweak DrawShip sample

samplecode/SampleApp.cpp

Index: samplecode/SampleApp.cpp
diff --git a/samplecode/SampleApp.cpp b/samplecode/SampleApp.cpp
index 07a7a87b7fb2ac83b68a7f927d05ec751b456e99..462f1b0882fe6ecdfde43ab32bf64df7ca1249b3 100644
--- a/samplecode/SampleApp.cpp
+++ b/samplecode/SampleApp.cpp
@@ -1803,6 +1803,10 @@ void SampleWindow::toggleFPS() {
 }
 
 void SampleWindow::toggleDistanceFieldFonts() {
+    // reset backend
+    fDevManager->tearDownBackend(this);
+    fDevManager->setUpBackend(this, fMSAASampleCount);
+
     SkSurfaceProps props = this->getSurfaceProps();
     uint32_t flags = props.flags() ^ SkSurfaceProps::kUseDeviceIndependentFonts_Flag;
     this->setSurfaceProps(SkSurfaceProps(flags, props.pixelGeometry()));