cc: Cleanup class/struct forward declarations

cc/output/gl_renderer.h

Index: cc/output/gl_renderer.h
diff --git a/cc/output/gl_renderer.h b/cc/output/gl_renderer.h
index 07ede049a7274ee93edda2d37c7e425dc0b1d36c..e666633cfa09458037c854466a1bdd9dd5f4fb9b 100644
--- a/cc/output/gl_renderer.h
+++ b/cc/output/gl_renderer.h
@@ -24,8 +24,6 @@
 #include "ui/events/latency_info.h"
 #include "ui/gfx/geometry/quad_f.h"
 
-class SkBitmap;
-
 namespace gpu {
 namespace gles2 {
 class GLES2Interface;
@@ -35,7 +33,6 @@ class GLES2Interface;
 namespace cc {
 class GLRendererShaderTest;
 class OutputSurface;
-class PictureDrawQuad;
 class Resource;
 class ResourcePool;
 class ScopedResource;
@@ -44,7 +41,6 @@ class TextureDrawQuad;
 class TextureMailboxDeleter;
 class StaticGeometryBinding;
 class DynamicGeometryBinding;
-class ScopedEnsureFramebufferAllocation;
 struct DrawRenderPassDrawQuadParams;
 
 // Class that handles drawing of composited render layers using GL.