--- a/gfx/layers/opengl/ImageLayerOGL.cpp
+++ b/gfx/layers/opengl/ImageLayerOGL.cpp
@@ -655,17 +655,17 @@ PlanarYCbCrImageOGL::UpdateTextures(GLCo
                      LOCAL_GL_UNSIGNED_BYTE,
                      mData.mCrChannel);
 
   // Reset alignment to default
   gl->fPixelStorei(LOCAL_GL_UNPACK_ALIGNMENT, 4);
 }
 
 CairoImageOGL::CairoImageOGL(LayerManagerOGL *aManager)
-  : CairoImage(nsnull)
+  : CairoImage(nsnull), mSize(0, 0)
 {
   NS_ASSERTION(NS_IsMainThread(), "Should be on main thread to create a cairo image");
 
   if (aManager) {
     // Allocate texture now to grab a reference to the GLContext
     mTexture.Allocate(aManager->glForResources());
   }
 }