Check for xfer barriers in GrBatch, auto-issue barriers in GrGpu

src/gpu/gl/GrGLGpu.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "GrGLGpu.h"
 #include "GrGLGLSL.h"
@@ skipping 3044 matching lines @@
     if (dstFBO) {
         this->unbindTextureFromFBO(GR_GL_DRAW_FRAMEBUFFER);
     }
     if (srcFBO) {
         this->unbindTextureFromFBO(GR_GL_READ_FRAMEBUFFER);
     }
     return true;
 }
 
 void GrGLGpu::xferBarrier(GrRenderTarget* rt, GrXferBarrierType type) {
+    SkASSERT(type);
     switch (type) {
         case kTexture_GrXferBarrierType: {
             GrGLRenderTarget* glrt = static_cast<GrGLRenderTarget*>(rt);
             if (glrt->textureFBOID() != glrt->renderFBOID()) {
                 // The render target uses separate storage so no need for glTextureBarrier.
                 // FIXME: The render target will resolve automatically when its texture is bound,
                 // but we could resolve only the bounds that will be read if we do it here instead.
                 return;
             }
             SkASSERT(this->caps()->textureBarrierSupport());
             GL_CALL(TextureBarrier());
             return;
         }
         case kBlend_GrXferBarrierType:
             SkASSERT(GrCaps::kAdvanced_BlendEquationSupport ==
                      this->caps()->blendEquationSupport());
             GL_CALL(BlendBarrier());
             return;
+        default: break; // placate compiler warnings that kNone not handled
     }
 }
 
 void GrGLGpu::didAddGpuTraceMarker() {
     if (this->caps()->gpuTracingSupport()) {
         const GrTraceMarkerSet& markerArray = this->getActiveTraceMarkers();
         SkString markerString = markerArray.toStringLast();
 #if GR_FORCE_GPU_TRACE_DEBUGGING
         SkDebugf("%s\n", markerString.c_str());
 #else
@@ skipping 101 matching lines @@
             this->setVertexArrayID(gpu, 0);
         }
         int attrCount = gpu->glCaps().maxVertexAttributes();
         if (fDefaultVertexArrayAttribState.count() != attrCount) {
             fDefaultVertexArrayAttribState.resize(attrCount);
         }
         attribState = &fDefaultVertexArrayAttribState;
     }
     return attribState;
 }