Bug 924679. Part 4: Add Factory::CreateSourceSurfaceForCairoSurface. r=mattwoodrow

--HG--
extra : rebase_source : 0c9187e8b9597e47e9d0d63d6da757db9a8c8a5c

gfx/2d/2D.h

@@ -937,6 +937,10 @@ public:
 
   static TemporaryRef<DrawTarget> CreateDrawTargetForCairoSurface(cairo_surface_t* aSurface, const IntSize& aSize);
 
+  static TemporaryRef<SourceSurface>
+    CreateSourceSurfaceForCairoSurface(cairo_surface_t* aSurface,
+                                       SurfaceFormat aFormat);
+
   static TemporaryRef<DrawTarget>
     CreateDrawTarget(BackendType aBackend, const IntSize &aSize, SurfaceFormat aFormat);
 

gfx/2d/DrawTargetCairo.cpp

@@ -1061,6 +1061,20 @@ DrawTargetCairo::CreateSourceSurfaceFromNativeSurface(const NativeSurface &aSurf
   return nullptr;
 }
 
+TemporaryRef<SourceSurface>
+DrawTargetCairo::CreateSourceSurfaceForCairoSurface(cairo_surface_t *aSurface,
+                                                    SurfaceFormat aFormat)
+{
+  IntSize size;
+  if (GetCairoSurfaceSize(aSurface, size)) {
+    RefPtr<SourceSurfaceCairo> source =
+      new SourceSurfaceCairo(aSurface, size, aFormat);
+    return source;
+  }
+
+  return nullptr;
+}
+
 TemporaryRef<DrawTarget>
 DrawTargetCairo::CreateSimilarDrawTarget(const IntSize &aSize, SurfaceFormat aFormat) const
 {

gfx/2d/DrawTargetCairo.h

@@ -157,6 +157,10 @@ public:
 
   static cairo_surface_t *GetDummySurface();
 
+  static TemporaryRef<SourceSurface>
+      CreateSourceSurfaceForCairoSurface(cairo_surface_t* aSurface,
+                                         SurfaceFormat aFormat);
+
 private: // methods
   // Init cairo surface without doing a cairo_surface_reference() call.
   bool InitAlreadyReferenced(cairo_surface_t* aSurface, const IntSize& aSize);

gfx/2d/Factory.cpp

@@ -554,6 +554,18 @@ Factory::CreateDrawTargetForCairoSurface(cairo_surface_t* aSurface, const IntSiz
   return retVal;
 }
 
+TemporaryRef<SourceSurface>
+Factory::CreateSourceSurfaceForCairoSurface(cairo_surface_t* aSurface,
+                                            SurfaceFormat aFormat)
+{
+  RefPtr<SourceSurface> retVal;
+
+#ifdef USE_CAIRO
+  retVal = DrawTargetCairo::CreateSourceSurfaceForCairoSurface(aSurface, aFormat);
+#endif
+  return retVal;
+}
+
 #ifdef XP_MACOSX
 TemporaryRef<DrawTarget>
 Factory::CreateDrawTargetForCairoCGContext(CGContextRef cg, const IntSize& aSize)