blimp: Cleanup class/struct forward declarations

blimp/client/test/compositor/test_blimp_embedder_compositor.h

Index: blimp/client/test/compositor/test_blimp_embedder_compositor.h
diff --git a/blimp/client/test/compositor/test_blimp_embedder_compositor.h b/blimp/client/test/compositor/test_blimp_embedder_compositor.h
index ce4c8ecc0c52180b16a8826dc705713b69ccc397..3dcd3ccf54bd9caf9f897556747e0608a2a89637 100644
--- a/blimp/client/test/compositor/test_blimp_embedder_compositor.h
+++ b/blimp/client/test/compositor/test_blimp_embedder_compositor.h
@@ -10,12 +10,6 @@
 #include "base/memory/weak_ptr.h"
 #include "blimp/client/support/compositor/blimp_embedder_compositor.h"
 
-class SkBitmap;
-
-namespace cc {
-class CopyOutputResult;
-}  // namespace cc
-
 namespace blimp {
 namespace client {
 class CompositorDependencies;