From 09eb9877d33c9b31bc824c7ebc59bcb9f6bf60b7 Mon Sep 17 00:00:00 2001
From: Joe Drew <joe@drew.ca>
Date: Thu, 11 Nov 2010 15:31:23 -0500
Subject: [PATCH] Bug 575521 - Add gfxQuartzSurface::GetAsImageSurface.
 r=jrmuizel,vlad

---
 gfx/thebes/gfxQuartzSurface.cpp | 17 +++++++++++++++++
 gfx/thebes/gfxQuartzSurface.h   |  2 ++
 2 files changed, 19 insertions(+)

diff --git a/gfx/thebes/gfxQuartzSurface.cpp b/gfx/thebes/gfxQuartzSurface.cpp
index 76cc57cb74b..f344386ea3b 100644
--- a/gfx/thebes/gfxQuartzSurface.cpp
+++ b/gfx/thebes/gfxQuartzSurface.cpp
@@ -117,6 +117,23 @@ PRInt32 gfxQuartzSurface::GetDefaultContextFlags() const
     return 0;
 }
 
+already_AddRefed<gfxImageSurface> gfxQuartzSurface::GetAsImageSurface()
+{
+    cairo_surface_t *surface = cairo_quartz_surface_get_image(mSurface);
+    if (!surface)
+        return nsnull;
+
+    nsRefPtr<gfxASurface> img = Wrap(surface);
+
+    // cairo_quartz_surface_get_image returns a referenced image, and thebes
+    // shares the refcounts of Cairo surfaces. However, Wrap also adds a
+    // reference to the image. We need to remove one of these references
+    // explicitly so we don't leak.
+    img->Release();
+
+    return static_cast<gfxImageSurface*>(img.forget().get());
+}
+
 gfxQuartzSurface::~gfxQuartzSurface()
 {
     CGContextRelease(mCGContext);
diff --git a/gfx/thebes/gfxQuartzSurface.h b/gfx/thebes/gfxQuartzSurface.h
index 25358a8cea6..65ac8fec8db 100644
--- a/gfx/thebes/gfxQuartzSurface.h
+++ b/gfx/thebes/gfxQuartzSurface.h
@@ -73,6 +73,8 @@ public:
 
     virtual PRInt32 GetDefaultContextFlags() const;
 
+    already_AddRefed<gfxImageSurface> GetAsImageSurface();
+
 protected:
     CGContextRef mCGContext;
     gfxSize      mSize;