Remove pre-attachment of stencil buffers

Change-Id: I4ef555a2b36cf3a0ec74e0ecf7e8ab4f8779df3e
Reviewed-on: https://skia-review.googlesource.com/49740
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
diff --git a/src/gpu/GrResourceProvider.cpp b/src/gpu/GrResourceProvider.cpp
index 0182baa..7f098e4 100644
--- a/src/gpu/GrResourceProvider.cpp
+++ b/src/gpu/GrResourceProvider.cpp
@@ -420,10 +420,10 @@
     return buffer;
 }
 
-GrStencilAttachment* GrResourceProvider::attachStencilAttachment(GrRenderTarget* rt) {
+bool GrResourceProvider::attachStencilAttachment(GrRenderTarget* rt) {
     SkASSERT(rt);
     if (rt->renderTargetPriv().getStencilAttachment()) {
-        return rt->renderTargetPriv().getStencilAttachment();
+        return true;
     }
 
     if (!rt->wasDestroyed() && rt->canAttemptStencilAttachment()) {
@@ -462,7 +462,7 @@
 #endif
         }
     }
-    return rt->renderTargetPriv().getStencilAttachment();
+    return SkToBool(rt->renderTargetPriv().getStencilAttachment());
 }
 
 sk_sp<GrRenderTarget> GrResourceProvider::wrapBackendTextureAsRenderTarget(