Bug 1330614 - avoid memory leak in FillRectWithMask. r=jrmuizel

MozReview-Commit-ID: 1rR3juCO1NB

--HG--
extra : rebase_source : 02a54ced3fcbbe0fa831c20a97cb0f0b950f5c84

gfx/layers/basic/BasicLayersImpl.cpp

@@ -170,6 +170,7 @@ FillRectWithMask(DrawTarget* aDT,
     mr->CopyRecording(buffer, size);
     std::istringstream recording(std::string(buffer, size));
 
+    delete [] buffer;
     translator->TranslateRecording(recording);
 
     aDT->SetTransform(oldTransform);