Bug 962288 - Don't call DeprecatedGetAsSurface unless it's Cairo. r=mattwoodrow

Changeset from Bug 959123 caused a performance decrease because
DeprecatedGetAsSurface was being called on an image that may not
be a CAIRO_SURFACE.

Reverted CairoImage surface members to public access as they were
before the patch from bug 959123.

gfx/layers/ImageContainer.h

@@ -960,8 +960,6 @@ public:
 
   CairoImage() : Image(nullptr, CAIRO_SURFACE) {}
 
-private:
-
   nsCountedRef<nsMainThreadSurfaceRef> mDeprecatedSurface;
   gfx::IntSize mSize;
 

gfx/layers/d3d10/ImageLayerD3D10.cpp

@@ -213,14 +213,14 @@ ImageLayerD3D10::RenderLayer()
 
   ID3D10EffectTechnique *technique;
   nsRefPtr<IDXGIKeyedMutex> keyedMutex;
-  nsRefPtr<gfxASurface> surf = image->DeprecatedGetAsSurface();
 
   if (image->GetFormat() == ImageFormat::CAIRO_SURFACE ||
       image->GetFormat() == ImageFormat::REMOTE_IMAGE_BITMAP ||
       image->GetFormat() == ImageFormat::REMOTE_IMAGE_DXGI_TEXTURE ||
       image->GetFormat() == ImageFormat::D3D9_RGB32_TEXTURE) {
     NS_ASSERTION(image->GetFormat() != ImageFormat::CAIRO_SURFACE ||
-                 !surf || surf->GetContentType() != gfxContentType::ALPHA,
+                 !static_cast<CairoImage*>(image)->mDeprecatedSurface ||
+                 static_cast<CairoImage*>(image)->mDeprecatedSurface->GetContentType() != gfxContentType::ALPHA,
                  "Image layer has alpha image");
     bool hasAlpha = false;
 

gfx/layers/d3d9/ImageLayerD3D9.cpp

@@ -414,9 +414,9 @@ ImageLayerD3D9::RenderLayer()
       image->GetFormat() == REMOTE_IMAGE_BITMAP ||
       image->GetFormat() == D3D9_RGB32_TEXTURE)
   {
-    nsRefPtr<gfxASurface> surf = image->DeprecatedGetAsSurface();
     NS_ASSERTION(image->GetFormat() != CAIRO_SURFACE ||
-                 !surf || surf->GetContentType() != gfxContentType::ALPHA,
+                 !static_cast<CairoImage*>(image)->mDeprecatedSurface ||
+                 static_cast<CairoImage*>(image)->mDeprecatedSurface->GetContentType() != gfxContentType::ALPHA,
                  "Image layer has alpha image");
 
     bool hasAlpha = false;