Recycle stencil buffers across render targets.

src/gpu/GrGpu.cpp

Index: src/gpu/GrGpu.cpp
diff --git a/src/gpu/GrGpu.cpp b/src/gpu/GrGpu.cpp
index eef965e5b61f4353f665d2652c506829b5c05ad9..27fed3c5820f2a40a539007f1790418e8825ae52 100644
--- a/src/gpu/GrGpu.cpp
+++ b/src/gpu/GrGpu.cpp
@@ -66,7 +66,7 @@ GrTexture* GrGpu::createTexture(const GrSurfaceDesc& desc, bool budgeted,
             !(kNoStencil_GrSurfaceFlag & desc.fFlags)) {
             SkASSERT(tex->asRenderTarget());
             // TODO: defer this and attach dynamically
-            if (!this->attachStencilBufferToRenderTarget(tex->asRenderTarget(), budgeted)) {
+            if (!this->attachStencilBufferToRenderTarget(tex->asRenderTarget())) {
                 tex->unref();
                 return NULL;
             }
@@ -84,12 +84,13 @@ GrTexture* GrGpu::createTexture(const GrSurfaceDesc& desc, bool budgeted,
     return tex;
 }
 
-bool GrGpu::attachStencilBufferToRenderTarget(GrRenderTarget* rt, bool budgeted) {
+bool GrGpu::attachStencilBufferToRenderTarget(GrRenderTarget* rt) {
     SkASSERT(NULL == rt->getStencilBuffer());
-    GrScratchKey sbKey;
-    GrStencilBuffer::ComputeKey(rt->width(), rt->height(), rt->numSamples(), &sbKey);
+    GrUniqueKey sbKey;
+    GrStencilBuffer::ComputeSharedStencilBufferKey(rt->width(), rt->height(), rt->numSamples(),
+                                                   &sbKey);
     SkAutoTUnref<GrStencilBuffer> sb(static_cast<GrStencilBuffer*>(
-        this->getContext()->getResourceCache()->findAndRefScratchResource(sbKey)));
+        this->getContext()->getResourceCache()->findAndRefUniqueResource(sbKey)));
     if (sb) {
         rt->setStencilBuffer(sb);
         bool attached = this->attachStencilBufferToRenderTarget(sb, rt);
@@ -98,7 +99,7 @@ bool GrGpu::attachStencilBufferToRenderTarget(GrRenderTarget* rt, bool budgeted)
         }
         return attached;
     }
-    if (this->createStencilBufferForRenderTarget(rt, budgeted, rt->width(), rt->height())) {
+    if (this->createStencilBufferForRenderTarget(rt, rt->width(), rt->height())) {
         // Right now we're clearing the stencil buffer here after it is
         // attached to an RT for the first time. When we start matching
         // stencil buffers with smaller color targets this will no longer
@@ -108,6 +109,7 @@ bool GrGpu::attachStencilBufferToRenderTarget(GrRenderTarget* rt, bool budgeted)
         // FBO. But iOS doesn't allow a stencil-only FBO. It reports unsupported
         // FBO status.
         this->clearStencil(rt);
+        rt->getStencilBuffer()->resourcePriv().setUniqueKey(sbKey);
         return true;
     } else {
         return false;
@@ -122,8 +124,7 @@ GrTexture* GrGpu::wrapBackendTexture(const GrBackendTextureDesc& desc) {
     }
     // TODO: defer this and attach dynamically
     GrRenderTarget* tgt = tex->asRenderTarget();
-    if (tgt &&
-        !this->attachStencilBufferToRenderTarget(tgt, true /*budgeted*/)) {
+    if (tgt && !this->attachStencilBufferToRenderTarget(tgt)) {
         tex->unref();
         return NULL;
     } else {