Recycle stencil buffers across render targets.

src/gpu/gl/GrGLStencilBuffer.h

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #ifndef GrGLStencilBuffer_DEFINED
 #define GrGLStencilBuffer_DEFINED
 
 #include "gl/GrGLInterface.h"
 #include "GrStencilBuffer.h"
 
 class GrGLStencilBuffer : public GrStencilBuffer {
 public:
     static const GrGLenum kUnknownInternalFormat = ~0U;
     static const GrGLuint kUnknownBitCount = ~0U;
     struct Format {
         GrGLenum  fInternalFormat;
         GrGLuint  fStencilBits;
         GrGLuint  fTotalBits;
         bool      fPacked;
     };
 
     struct IDDesc {
+        IDDesc() : fRenderbufferID(0), fLifeCycle(kCached_LifeCycle) {}
         GrGLuint fRenderbufferID;
         GrGpuResource::LifeCycle fLifeCycle;
     };
 
     GrGLStencilBuffer(GrGpu* gpu,
                       const IDDesc& idDesc,
                       int width, int height,
                       int sampleCnt,
                       const Format& format)
         : GrStencilBuffer(gpu, idDesc.fLifeCycle, width, height, format.fStencilBits, sampleCnt)
@@ skipping 19 matching lines @@
     Format fFormat;
     // may be zero for external SBs associated with external RTs
     // (we don't require the client to give us the id, just tell
     // us how many bits of stencil there are).
     GrGLuint fRenderbufferID;
 
     typedef GrStencilBuffer INHERITED;
 };
 
 #endif