Make cc::CompositorFrames movable [Part 1 of 2]

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 2cc3a4640e34a40ad3554b6cfbce90e65f662cf8..9c585136af10a95a0da141a4b68f9e1a88d33617 100644
--- a/android_webview/browser/child_frame.h
+++ b/android_webview/browser/child_frame.h
@@ -9,6 +9,8 @@
 
 #include "android_webview/browser/compositor_id.h"
 #include "base/macros.h"
+#include "base/optional.h"
+#include "cc/output/compositor_frame.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/geometry/size.h"
 #include "ui/gfx/transform.h"
@@ -22,7 +24,7 @@ namespace android_webview {
 class ChildFrame {
  public:
   ChildFrame(uint32_t output_surface_id,
-             std::unique_ptr<cc::CompositorFrame> frame,
+             cc::CompositorFrame frame,
              const CompositorID& compositor_id,
              bool viewport_rect_for_tile_priority_empty,
              const gfx::Transform& transform_for_tile_priority,
@@ -31,7 +33,7 @@ class ChildFrame {
   ~ChildFrame();
 
   const uint32_t output_surface_id;
-  std::unique_ptr<cc::CompositorFrame> frame;
+  base::Optional<cc::CompositorFrame> frame;
   // The id of the compositor this |frame| comes from.
   const CompositorID compositor_id;
   const bool viewport_rect_for_tile_priority_empty;