Add GrGpu support for Vulkan command buffer flush

src/gpu/gl/GrGLGpu.cpp

Index: src/gpu/gl/GrGLGpu.cpp
diff --git a/src/gpu/gl/GrGLGpu.cpp b/src/gpu/gl/GrGLGpu.cpp
index e29a7f81f317aa189e7263dc23416263cb264e8e..a03463a9118034a8aa8cbfbe0553c88d215ca997 100644
--- a/src/gpu/gl/GrGLGpu.cpp
+++ b/src/gpu/gl/GrGLGpu.cpp
@@ -2417,7 +2417,7 @@ bool GrGLGpu::onReadPixels(GrSurface* surface,
     return true;
 }
 
-void GrGLGpu::performFlushWorkaround() {
+void GrGLGpu::finishDrawTarget() {
     if (fPLSHasBeenUsed) {
         /* There is an ARM driver bug where if we use PLS, and then draw a frame which does not 
          * use PLS, it leaves garbage all over the place. As a workaround, we use PLS in a