enable skia gradients, fix bugs

core/fxge/skia/fx_skia_device.cpp

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <algorithm>
 #include <utility>
 #include <vector>
 
 #include "core/fpdfapi/page/cpdf_meshstream.h"
 #include "core/fpdfapi/page/cpdf_shadingpattern.h"
@@ skipping 1734 matching lines @@
                             nullptr, nullptr);
   SkCanvas canvas(skDstBitmap);
   canvas.drawBitmap(skSrcBitmap, left, top, nullptr);
   return true;
 #endif  // _SKIA_SUPPORT_
 
 #ifdef _SKIA_SUPPORT_PATHS_
   m_pBitmap->UnPreMultiply();
   FX_RECT rect(left, top, left + pBitmap->GetWidth(),
                top + pBitmap->GetHeight());
-  CFX_DIBitmap* pBack = nullptr;
+  std::unique_ptr<CFX_DIBitmap> pBack = nullptr;
   if (m_pOriDevice) {
     pBack = m_pOriDevice->Clone(&rect);
     if (!pBack)
       return true;
 
     pBack->CompositeBitmap(0, 0, pBack->GetWidth(), pBack->GetHeight(),
                            m_pBitmap, 0, 0);
   } else {
     pBack = m_pBitmap->Clone(&rect);
     if (!pBack)
       return true;
   }
 
   bool bRet = true;
   left = std::min(left, 0);
   top = std::min(top, 0);
   if (m_bRgbByteOrder) {
     RgbByteOrderTransferBitmap(pBitmap, 0, 0, rect.Width(), rect.Height(),
-                               pBack, left, top);
+                               pBack.get(), left, top);
   } else {
-    bRet = pBitmap->TransferBitmap(0, 0, rect.Width(), rect.Height(), pBack,
-                                   left, top);
+    bRet = pBitmap->TransferBitmap(0, 0, rect.Width(), rect.Height(),
+                                   pBack.get(), left, top);
   }
-  delete pBack;
   return bRet;
 #endif  // _SKIA_SUPPORT_PATHS_
 }
 
 CFX_DIBitmap* CFX_SkiaDeviceDriver::GetBackDrop() {
   return m_pOriDevice;
 }
 
 bool CFX_SkiaDeviceDriver::SetDIBits(const CFX_DIBSource* pBitmap,
                                      uint32_t argb,
@@ skipping 1216 matching lines @@
       }
     }
     if (m_pDevice->GetBPP() == 1) {
       composite_span = &CFX_Renderer::CompositeSpan1bpp;
     }
     return true;
   }
 };
 
 #endif  // _SKIA_SUPPORT_PATHS_