Add wrapBackendTextureAsRenderTarget API

src/image/SkSurface_Gpu.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkSurface_Gpu.h"
 
+#include "GrResourceProvider.h"
 #include "SkCanvas.h"
 #include "SkGpuDevice.h"
 #include "SkImage_Base.h"
 #include "SkImage_Gpu.h"
 #include "SkImagePriv.h"
 #include "SkSurface_Base.h"
 
 #if SK_SUPPORT_GPU
 
 SkSurface_Gpu::SkSurface_Gpu(SkGpuDevice* device)
@@ skipping 81 matching lines @@
         SkTextureImageApplyBudgetedDecision(image);
     } else if (kDiscard_ContentChangeMode == mode) {
         this->SkSurface_Gpu::onDiscard();
     }
 }
 
 void SkSurface_Gpu::onDiscard() {
     fDevice->accessRenderTarget()->discard();
 }
 
+void SkSurface_Gpu::onPrepareForExternalIO() {
+    fDevice->accessRenderTarget()->prepareForExternalIO();
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 
 SkSurface* SkSurface::NewRenderTargetDirect(GrRenderTarget* target, const SkSurfaceProps* props) {
     SkAutoTUnref<SkGpuDevice> device(
         SkGpuDevice::Create(target, props, SkGpuDevice::kUninit_InitContents));
     if (!device) {
         return nullptr;
     }
     return new SkSurface_Gpu(device);
 }
@@ skipping 42 matching lines @@
         return nullptr;
     }
     SkAutoTUnref<SkGpuDevice> device(SkGpuDevice::Create(rt, props,
                                                          SkGpuDevice::kUninit_InitContents));
     if (!device) {
         return nullptr;
     }
     return new SkSurface_Gpu(device);
 }
 
+SkSurface* SkSurface::NewFromBackendTextureAsRenderTarget(GrContext* context,
+                                                          const GrBackendTextureDesc& desc,
+                                                          const SkSurfaceProps* props) {
+    if (nullptr == context) {
+        return nullptr;
+    }
+    SkAutoTUnref<GrRenderTarget> rt(
+            context->resourceProvider()->wrapBackendTextureAsRenderTarget(desc));
+    if (!rt) {
+        return nullptr;
+    }
+    SkAutoTUnref<SkGpuDevice> device(SkGpuDevice::Create(rt, props,
+                                                         SkGpuDevice::kUninit_InitContents));
+    if (!device) {
+        return nullptr;
+    }
+    return new SkSurface_Gpu(device);
+}
+
 #endif