Remove unnessary uniform barriers in Vulkan.

src/gpu/vk/GrVkGpu.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrVkGpu.h"
 
 #include "GrContextOptions.h"
@@ skipping 1478 matching lines @@
                      const GrMesh* meshes,
                      int meshCount) {
     if (!meshCount) {
         return;
     }
     GrRenderTarget* rt = pipeline.getRenderTarget();
     GrVkRenderTarget* vkRT = static_cast<GrVkRenderTarget*>(rt);
     const GrVkRenderPass* renderPass = vkRT->simpleRenderPass();
     SkASSERT(renderPass);
 
-
     GrPrimitiveType primitiveType = meshes[0].primitiveType();
     sk_sp<GrVkPipelineState> pipelineState = this->prepareDrawState(pipeline,
                                                                     primProc,
                                                                     primitiveType,
                                                                     *renderPass);
     if (!pipelineState) {
         return;
     }
 
     // Change layout of our render target so it can be used as the color attachment
@@ skipping 36 matching lines @@
         GrMesh::Iterator iter;
         const GrNonInstancedMesh* nonIdxMesh = iter.init(mesh);
         do {
             if (nonIdxMesh->primitiveType() != primitiveType) {
                 // Technically we don't have to call this here (since there is a safety check in
                 // pipelineState:setData but this will allow for quicker freeing of resources if the
                 // pipelineState sits in a cache for a while.
                 pipelineState->freeTempResources(this);
                 SkDEBUGCODE(pipelineState = nullptr);
                 primitiveType = nonIdxMesh->primitiveType();
-                // It is illegal for us to have the necessary memory barriers for when we write and
-                // update the uniform buffers in prepareDrawState while in an active render pass.
-                // Thus we must end the current one and then start it up again.
-                fCurrentCmdBuffer->endRenderPass(this);
                 pipelineState = this->prepareDrawState(pipeline,
                                                        primProc,
                                                        primitiveType,
                                                        *renderPass);
                 if (!pipelineState) {
                     return;
                 }
-                fCurrentCmdBuffer->beginRenderPass(this, renderPass, *vkRT);
             }
             SkASSERT(pipelineState);
             this->bindGeometry(primProc, *nonIdxMesh);
 
             if (nonIdxMesh->isIndexed()) {
                 fCurrentCmdBuffer->drawIndexed(this,
                                                nonIdxMesh->indexCount(),
                                                1,
                                                nonIdxMesh->startIndex(),
                                                nonIdxMesh->startVertex(),
@@ skipping 23 matching lines @@
     aglSwapBuffers(aglGetCurrentContext());
     int set_a_break_pt_here = 9;
     aglSwapBuffers(aglGetCurrentContext());
 #elif defined(SK_BUILD_FOR_WIN32)
     SwapBuf();
     int set_a_break_pt_here = 9;
     SwapBuf();
 #endif
 #endif
 }