Add support for creating texture backed images where Skia will delete the texture.

src/gpu/GrTexture.cpp

 
 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrContext.h"
 #include "GrCaps.h"
@@ skipping 63 matching lines @@
         return desc.fOrigin;
     }
 }
 }
 
 //////////////////////////////////////////////////////////////////////////////
 GrTexture::GrTexture(GrGpu* gpu, LifeCycle lifeCycle, const GrSurfaceDesc& desc)
     : INHERITED(gpu, lifeCycle, desc)
     , fMipMapsStatus(kNotAllocated_MipMapsStatus) {
 
-    if (kWrapped_LifeCycle != lifeCycle && !GrPixelConfigIsCompressed(desc.fConfig)) {
+    if (!this->isExternal() && !GrPixelConfigIsCompressed(desc.fConfig)) {
         GrScratchKey key;
         GrTexturePriv::ComputeScratchKey(desc, &key);
         this->setScratchKey(key);
     }
     // only make sense if alloc size is pow2
     fShiftFixedX = 31 - SkCLZ(fDesc.fWidth);
     fShiftFixedY = 31 - SkCLZ(fDesc.fHeight);
 }
 
 void GrTexturePriv::ComputeScratchKey(const GrSurfaceDesc& desc, GrScratchKey* key) {
     static const GrScratchKey::ResourceType kType = GrScratchKey::GenerateResourceType();
 
     GrScratchKey::Builder builder(key, kType, 2);
 
     GrSurfaceOrigin origin = resolve_origin(desc);
     uint32_t flags = desc.fFlags & ~kCheckAllocation_GrSurfaceFlag;
 
     SkASSERT(desc.fWidth <= SK_MaxU16);
     SkASSERT(desc.fHeight <= SK_MaxU16);
     SkASSERT(static_cast<int>(desc.fConfig) < (1 << 6));
     SkASSERT(desc.fSampleCnt < (1 << 8));
     SkASSERT(flags < (1 << 10));
     SkASSERT(static_cast<int>(origin) < (1 << 8));
 
     builder[0] = desc.fWidth | (desc.fHeight << 16);
     builder[1] = desc.fConfig | (desc.fSampleCnt << 6) | (flags << 14) | (origin << 24);
 }