Fix vulkan dual source blending

src/gpu/vk/GrVkPipelineStateBuilder.cpp

 /*
 * Copyright 2016 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */
 
 #include "vk/GrVkPipelineStateBuilder.h"
 
 #include "vk/GrVkGpu.h"
@@ skipping 32 matching lines @@
 }
 
 const GrCaps* GrVkPipelineStateBuilder::caps() const {
     return fGpu->caps();
 }
 const GrGLSLCaps* GrVkPipelineStateBuilder::glslCaps() const {
     return fGpu->vkCaps().glslCaps();
 }
 
 void GrVkPipelineStateBuilder::finalizeFragmentOutputColor(GrGLSLShaderVar& outputColor) {
-    outputColor.setLayoutQualifier("location = 0");
+    outputColor.setLayoutQualifier("location = 0, index = 0");
 }
 
 void GrVkPipelineStateBuilder::finalizeFragmentSecondaryColor(GrGLSLShaderVar& outputColor) {
-    outputColor.setLayoutQualifier("location = 1");
+    outputColor.setLayoutQualifier("location = 0, index = 1");
 }
 
 VkShaderStageFlags visibility_to_vk_stage_flags(uint32_t visibility) {
     VkShaderStageFlags flags = 0;
 
     if (visibility & kVertex_GrShaderFlag) {
         flags |= VK_SHADER_STAGE_VERTEX_BIT;
     }
     if (visibility & kGeometry_GrShaderFlag) {
         flags |= VK_SHADER_STAGE_GEOMETRY_BIT;
@@ skipping 34 matching lines @@
     shaderc_compilation_result_t result = nullptr;
 
     if (gpu->vkCaps().canUseGLSLForShaderModule()) {
         moduleCreateInfo.codeSize = strlen(shaderString.c_str());
         moduleCreateInfo.pCode = (const uint32_t*)shaderString.c_str();
     } else {
 
         shaderc_compiler_t compiler = gpu->shadercCompiler();
 
         shaderc_compile_options_t options = shaderc_compile_options_initialize();
-        shaderc_compile_options_set_forced_version_profile(options, 140, shaderc_profile_none);
 
         shaderc_shader_kind shadercStage = vk_shader_stage_to_shaderc_kind(stage);
         result = shaderc_compile_into_spv(compiler,
                                           shaderString.c_str(),
                                           strlen(shaderString.c_str()),
                                           shadercStage,
                                           "shader",
                                           "main",
                                           options);
         shaderc_compile_options_release(options);
@@ skipping 172 matching lines @@
                                  dsLayout,
                                  fUniformHandles,
                                  fUniformHandler.fUniforms,
                                  fUniformHandler.fCurrentVertexUBOOffset,
                                  fUniformHandler.fCurrentFragmentUBOOffset,
                                  numSamplers,
                                  fGeometryProcessor,
                                  fXferProcessor,
                                  fFragmentProcessors);
 }