initial checkin of SkSL compiler

src/gpu/vk/GrVkGpu.cpp

Index: src/gpu/vk/GrVkGpu.cpp
diff --git a/src/gpu/vk/GrVkGpu.cpp b/src/gpu/vk/GrVkGpu.cpp
index e5d24fc5806ff8044a55da6416b311f9c9bcb8f3..f15677580df7bc632e01c30b614acb49e60458dd 100644
--- a/src/gpu/vk/GrVkGpu.cpp
+++ b/src/gpu/vk/GrVkGpu.cpp
@@ -36,6 +36,10 @@
 #include "vk/GrVkInterface.h"
 #include "vk/GrVkTypes.h"
 
+#if USE_SKSL
+#include "SkSLCompiler.h"
+#endif
+
 #define VK_CALL(X) GR_VK_CALL(this->vkInterface(), X)
 #define VK_CALL_RET(RET, X) GR_VK_CALL_RET(this->vkInterface(), RET, X)
 #define VK_CALL_ERRCHECK(X) GR_VK_CALL_ERRCHECK(this->vkInterface(), X)
@@ -110,7 +114,11 @@ GrVkGpu::GrVkGpu(GrContext* context, const GrContextOptions& options,
     }
 #endif
 
+#if USE_SKSL
+    fCompiler = new SkSL::Compiler();
+#else
     fCompiler = shaderc_compiler_initialize();
+#endif
 
     fVkCaps.reset(new GrVkCaps(options, this->vkInterface(), backendCtx->fPhysicalDevice,
                                backendCtx->fFeatures, backendCtx->fExtensions));
@@ -176,7 +184,11 @@ GrVkGpu::~GrVkGpu() {
 
     VK_CALL(DestroyCommandPool(fDevice, fCmdPool, nullptr));
 
+#if USE_SKSL
+    delete fCompiler;
+#else
     shaderc_compiler_release(fCompiler);
+#endif
 
 #ifdef ENABLE_VK_LAYERS
     if (fCallback) {