Bug 1251808 - Construct the SourceSurfaceImage with the correct size in RasterImage::GetCurrentImage(). r=seth

gfx/layers/ImageContainer.cpp

@@ -549,6 +549,12 @@ SourceSurfaceImage::SourceSurfaceImage(const gfx::IntSize& aSize, gfx::SourceSur
     mSourceSurface(aSourceSurface)
 {}
 
+SourceSurfaceImage::SourceSurfaceImage(gfx::SourceSurface* aSourceSurface)
+  : Image(nullptr, ImageFormat::CAIRO_SURFACE),
+    mSize(aSourceSurface->GetSize()),
+    mSourceSurface(aSourceSurface)
+{}
+
 SourceSurfaceImage::~SourceSurfaceImage()
 {
 }

gfx/layers/ImageContainer.h

@@ -824,6 +824,7 @@ public:
   virtual gfx::IntSize GetSize() override { return mSize; }
 
   SourceSurfaceImage(const gfx::IntSize& aSize, gfx::SourceSurface* aSourceSurface);
+  SourceSurfaceImage(gfx::SourceSurface* aSourceSurface);
   ~SourceSurfaceImage();
 
 private:

image/RasterImage.cpp

@@ -628,11 +628,7 @@ RasterImage::GetCurrentImage(ImageContainer* aContainer, uint32_t aFlags)
     return MakePair(drawResult, RefPtr<layers::Image>());
   }
 
-  IntSize size;
-  GetWidth(&size.width);
-  GetHeight(&size.height);
-
-  RefPtr<layers::Image> image = new layers::SourceSurfaceImage(size, surface);
+  RefPtr<layers::Image> image = new layers::SourceSurfaceImage(surface);
   return MakePair(drawResult, Move(image));
 }