Add Gr*Proxy classes

src/gpu/GrRenderTargetProxy.cpp

Index: src/gpu/GrRenderTargetProxy.cpp
diff --git a/src/gpu/GrRenderTargetProxy.cpp b/src/gpu/GrRenderTargetProxy.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..e4071e5d032f013f9e719d2f44bb343f15142cc2
--- /dev/null
+++ b/src/gpu/GrRenderTargetProxy.cpp
@@ -0,0 +1,77 @@
+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "GrRenderTargetProxy.h"
+
+#include "GrDrawTarget.h"
+#include "GrGpuResourcePriv.h"
+#include "GrRenderTargetPriv.h"
+
+GrRenderTargetProxy::GrRenderTargetProxy(sk_sp<GrRenderTarget> rt)
+    : INHERITED(rt->desc(), kExact_BackingFit, rt->resourcePriv().isBudgeted())
+    , fTarget(std::move(rt))
+    , fSampleConfig(fTarget->renderTargetPriv().sampleConfig())
+    , fLastDrawTarget(nullptr) {
+}
+
+GrRenderTargetProxy::~GrRenderTargetProxy() {
+    if (fLastDrawTarget) {
+        fLastDrawTarget->clearRT();
+    }
+    SkSafeUnref(fLastDrawTarget);
+}
+
+GrRenderTarget* GrRenderTargetProxy::instantiate(GrTextureProvider* texProvider) {
+    if (fTarget) {
+        return fTarget.get();
+    }
+
+    // TODO: it would be nice to not have to copy the desc here
+    GrSurfaceDesc desc = fDesc;
+    desc.fFlags |= GrSurfaceFlags::kRenderTarget_GrSurfaceFlag;
+
+    sk_sp<GrTexture> tex;
+    if (kApprox_BackingFit == fFit) {
+        tex.reset(texProvider->createApproxTexture(desc));
+    } else {
+        tex.reset(texProvider->createTexture(desc, fBudgeted));
+    }
+    if (!tex || !tex->asRenderTarget()) {
+        return nullptr;
+    }
+
+    fTarget.reset(tex->asRenderTarget());
+
+    // Check that our a priori computation matched the ultimate reality
+    SkASSERT(fSampleConfig == fTarget->renderTargetPriv().sampleConfig());
+
+    return fTarget.get();
+}
+
+void GrRenderTargetProxy::setLastDrawTarget(GrDrawTarget* dt) {
+    if (fLastDrawTarget) {
+        // The non-MDB world never closes so we can't check this condition
+#ifdef ENABLE_MDB
+        SkASSERT(fLastDrawTarget->isClosed());
+#endif
+        fLastDrawTarget->clearRT();
+    }
+
+    SkRefCnt_SafeAssign(fLastDrawTarget, dt);
+}
+
+sk_sp<GrRenderTargetProxy> GrRenderTargetProxy::Make(const GrCaps& caps,
+                                                     const GrSurfaceDesc& desc,
+                                                     BackingFit fit,
+                                                     SkBudgeted budgeted) {
+    return sk_sp<GrRenderTargetProxy>(new GrRenderTargetProxy(caps, desc, fit, budgeted));
+}
+
+sk_sp<GrRenderTargetProxy> GrRenderTargetProxy::Make(sk_sp<GrRenderTarget> rt) {
+    return sk_sp<GrRenderTargetProxy>(new GrRenderTargetProxy(rt));
+}
+