loplugin:useuniqueptr in QuartzSalBitmap::CreateColorMask

Change-Id: I7fbebf3730aa79209a3ad954522ad8695e5d8c24
Reviewed-on: https://gerrit.libreoffice.org/60704
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

vcl/quartz/salbmp.cxx

@@ -937,8 +937,8 @@ CGImageRef QuartzSalBitmap::CreateColorMask( int nX, int nY, int nWidth,
     if (m_pUserBuffer.get() && (nX + nWidth <= mnWidth) && (nY + nHeight <= mnHeight))
     {
         const sal_uInt32 nDestBytesPerRow = nWidth << 2;
-        sal_uInt32* pMaskBuffer = static_cast<sal_uInt32*>( std::malloc( nHeight * nDestBytesPerRow ) );
-        sal_uInt32* pDest = pMaskBuffer;
+        std::unique_ptr<sal_uInt32[]> pMaskBuffer(new (std::nothrow) sal_uInt32[ nHeight * nDestBytesPerRow / 4] );
+        sal_uInt32* pDest = pMaskBuffer.get();
 
         ImplPixelFormat* pSourcePixels = ImplPixelFormat::GetFormat( mnBits, maPalette );
 
@@ -967,15 +967,11 @@ CGImageRef QuartzSalBitmap::CreateColorMask( int nX, int nY, int nWidth,
                 pSource += mnBytesPerRow;
             }
 
-            CGDataProviderRef xDataProvider( CGDataProviderCreateWithData(nullptr, pMaskBuffer, nHeight * nDestBytesPerRow, &CFRTLFree) );
+            CGDataProviderRef xDataProvider( CGDataProviderCreateWithData(nullptr, pMaskBuffer.release(), nHeight * nDestBytesPerRow, &CFRTLFree) );
             xMask = CGImageCreate(nWidth, nHeight, 8, 32, nDestBytesPerRow, GetSalData()->mxRGBSpace, kCGImageAlphaPremultipliedFirst, xDataProvider, nullptr, true, kCGRenderingIntentDefault);
             SAL_INFO("vcl.cg", "CGImageCreate(" << nWidth << "x" << nHeight << "x8) = " << xMask );
             CFRelease(xDataProvider);
         }
-        else
-        {
-            free(pMaskBuffer);
-        }
 
         delete pSourcePixels;
     }