wm: Fix an uncommon memory leak in the compositor code.

compositor/mock_compositor.h

 // Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef WINDOW_MANAGER_COMPOSITOR_MOCK_COMPOSITOR_H_
 #define WINDOW_MANAGER_COMPOSITOR_MOCK_COMPOSITOR_H_
 
 #include <set>
 
 #include "base/logging.h"
@@ skipping 186 matching lines @@
 
    private:
     DISALLOW_COPY_AND_ASSIGN(ImageActor);
   };
 
   class TexturePixmapActor : public MockCompositor::Actor,
                              public Compositor::TexturePixmapActor {
    public:
     explicit TexturePixmapActor(XConnection* xconn);
     virtual ~TexturePixmapActor();
-    const uint8_t* alpha_mask_bytes() const { return alpha_mask_bytes_; }
+    const uint8_t* alpha_mask_bytes() const { return alpha_mask_bytes_.get(); }
     XID pixmap() const { return pixmap_; }
     int num_texture_updates() const { return num_texture_updates_; }
 
     // Begin Compositor::TexturePixmapActor methods.
     virtual void SetPixmap(XID pixmap);
     virtual void UpdateTexture() { num_texture_updates_++; }
     virtual void SetAlphaMask(const uint8_t* bytes, int width, int height);
     virtual void ClearAlphaMask();
     virtual void MergeDamagedRegion(const Rect& region);
     virtual const Rect& GetDamagedRegion() const;
     virtual void ResetDamagedRegion();
     // End Compositor::TexturePixmapActor methods.
 
    private:
     XConnection* xconn_;  // not owned
 
     // Shape as set by SetAlphaMask(), or NULL if the actor is unshaped.
-    uint8_t* alpha_mask_bytes_;
+    scoped_array<uint8_t> alpha_mask_bytes_;
 
     // Redirected window that we're tracking.
     XWindow redirected_window_;
 
     // Pixmap that we're displaying.
     XID pixmap_;
 
     // Number of times that UpdateTexture() has been called.
     int num_texture_updates_;
 
@@ skipping 45 matching lines @@
   StageActor default_stage_;
   std::tr1::unordered_set<int> active_visibility_groups_;
   int num_draws_;
 
   DISALLOW_COPY_AND_ASSIGN(MockCompositor);
 };
 
 }  // namespace window_manager
 
 #endif  // WINDOW_MANAGER_COMPOSITOR_MOCK_COMPOSITOR_H_