Add ability to write out VkPipelineCache to gpu PersistentCache.

Bug: skia:
Change-Id: Id13d680401f69a074ae0c85f9ceaf3308fccb129
Reviewed-on: https://skia-review.googlesource.com/c/181403
Commit-Queue: Greg Daniel <egdaniel@google.com>
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
diff --git a/src/gpu/GrContext.cpp b/src/gpu/GrContext.cpp
index 14a65fa..88d1ec2 100644
--- a/src/gpu/GrContext.cpp
+++ b/src/gpu/GrContext.cpp
@@ -397,6 +397,16 @@
     fContext->fDrawingManager->flush(proxy);
 }
 
+////////////////////////////////////////////////////////////////////////////////
+
+void GrContext::storeVkPipelineCacheData() {
+    if (fGpu) {
+        fGpu->storeVkPipelineCacheData();
+    }
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
 // TODO: This will be removed when GrSurfaceContexts are aware of their color types.
 // (skbug.com/6718)
 static bool valid_premul_config(GrPixelConfig config) {