cc: Adopt new skia object when it's created to avoid memory leak.

cc/output/software_renderer.cc

 // Copyright 2012 The Chromium 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 "cc/output/software_renderer.h"
 
 #include "base/debug/trace_event.h"
 #include "cc/base/math_util.h"
 #include "cc/output/compositor_frame.h"
 #include "cc/output/compositor_frame_ack.h"
@@ skipping 298 matching lines @@
   SkMatrix content_matrix;
   content_matrix.setRectToRect(
       gfx::RectFToSkRect(quad->tex_coord_rect),
       gfx::RectFToSkRect(QuadVertexRect()),
       SkMatrix::kFill_ScaleToFit);
   current_canvas_->concat(content_matrix);
 
   // TODO(aelias): This isn't correct in all cases. We should detect these
   // cases and fall back to a persistent bitmap backing
   // (http://crbug.com/280374).
+  skia::RefPtr<SkDrawFilter> opacity_filter =
+      skia::AdoptRef(new skia::OpacityDrawFilter(quad->opacity(), true));
   DCHECK(!current_canvas_->getDrawFilter());
-  current_canvas_->setDrawFilter(new skia::OpacityDrawFilter(quad->opacity(),
-                                                             true));
+  current_canvas_->setDrawFilter(opacity_filter.get());
 
   TRACE_EVENT0("cc",
                "SoftwareRenderer::DrawPictureQuad");
   quad->picture_pile->RasterDirect(
       current_canvas_, quad->content_rect, quad->contents_scale, NULL);
 
   current_canvas_->setDrawFilter(NULL);
 }
 
 void SoftwareRenderer::DrawSolidColorQuad(const DrawingFrame* frame,
@@ skipping 213 matching lines @@
     EnsureBackbuffer();
   else
     DiscardBackbuffer();
 }
 
 void SoftwareRenderer::SetDiscardBackBufferWhenNotVisible(bool discard) {
   // The software renderer always discards the backbuffer when not visible.
 }
 
 }  // namespace cc