ui: Cleanup class/struct forward declarations

android_webview/browser/child_frame.h

Index: android_webview/browser/child_frame.h
diff --git a/android_webview/browser/child_frame.h b/android_webview/browser/child_frame.h
index c0f9a71911ce06e02a06d6b38ad07bb7b6bc4d8f..13ce37960904357ae130be264634120ca8738fd2 100644
--- a/android_webview/browser/child_frame.h
+++ b/android_webview/browser/child_frame.h
@@ -9,6 +9,7 @@
 
 #include "android_webview/browser/compositor_id.h"
 #include "base/macros.h"
+#include "content/public/browser/android/synchronous_compositor.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/geometry/size.h"
 #include "ui/gfx/transform.h"
@@ -21,15 +22,23 @@ namespace android_webview {
 
 class ChildFrame {
  public:
-  ChildFrame(uint32_t compositor_frame_sink_id,
-             std::unique_ptr<cc::CompositorFrame> frame,
-             const CompositorID& compositor_id,
-             bool viewport_rect_for_tile_priority_empty,
-             const gfx::Transform& transform_for_tile_priority,
-             bool offscreen_pre_raster,
-             bool is_layer);
+  ChildFrame(
+      scoped_refptr<content::SynchronousCompositor::FrameFuture> frame_future,
+      uint32_t compositor_frame_sink_id,
+      std::unique_ptr<cc::CompositorFrame> frame,
+      const CompositorID& compositor_id,
+      bool viewport_rect_for_tile_priority_empty,
+      const gfx::Transform& transform_for_tile_priority,
+      bool offscreen_pre_raster,
+      bool is_layer);
   ~ChildFrame();
 
+  // Helper to move frame from |frame_future| to |frame|.
+  void WaitOnFutureIfNeeded();
+
+  // This is used in async ondraw path. The frame is either in |frame_future|
+  // or |frame|. It's illegal if both are non-null.
+  scoped_refptr<content::SynchronousCompositor::FrameFuture> frame_future;
   // These two fields are not const to make async path easier.
   uint32_t compositor_frame_sink_id;
   std::unique_ptr<cc::CompositorFrame> frame;