Propagate scrolling/marginwidth/marginheight property values to child frame.

content/browser/frame_host/frame_tree_node.h

Index: content/browser/frame_host/frame_tree_node.h
diff --git a/content/browser/frame_host/frame_tree_node.h b/content/browser/frame_host/frame_tree_node.h
index 2d033a65db6f56f0f7ad88b946186f2f8457c79c..6eb71070050a534e027a2513bebd4d18e8091ccb 100644
--- a/content/browser/frame_host/frame_tree_node.h
+++ b/content/browser/frame_host/frame_tree_node.h
@@ -15,6 +15,7 @@
 #include "content/browser/frame_host/render_frame_host_manager.h"
 #include "content/common/content_export.h"
 #include "content/common/frame_replication_state.h"
+#include "third_party/WebKit/public/web/WebFrameOwnerProperties.h"
 #include "url/gurl.h"
 #include "url/origin.h"
 
@@ -53,7 +54,8 @@ class CONTENT_EXPORT FrameTreeNode {
                 RenderFrameHostManager::Delegate* manager_delegate,
                 blink::WebTreeScopeType scope,
                 const std::string& name,
-                blink::WebSandboxFlags sandbox_flags);
+                blink::WebSandboxFlags sandbox_flags,
+                const blink::WebFrameOwnerProperties& frame_owner_properties);
 
   ~FrameTreeNode();
 
@@ -147,6 +149,14 @@ class CONTENT_EXPORT FrameTreeNode {
     return replication_state_;
   }
 
+  const blink::WebFrameOwnerProperties& frame_owner_properties() {
+    return frame_owner_properties_;
+  }
+
+  void SetScrollingMode(blink::WebFrameOwnerProperties::ScrollingMode mode);
+  void SetMarginWidth(int margin_width);
+  void SetMarginHeight(int margin_height);
+
   RenderFrameHostImpl* current_frame_host() const {
     return render_manager_.current_frame_host();
   }
@@ -276,6 +286,13 @@ class CONTENT_EXPORT FrameTreeNode {
   // flags when a navigation for this frame commits.
   blink::WebSandboxFlags effective_sandbox_flags_;
 
+  // Tracks the scrolling and margin properties for this frame.  These
+  // properties affect the child renderer but are available on its parent's
+  // frame element.  When a parent frame dynamically updates these properties,
+  // we store it here.  However, the update only takes effect on the next frame
+  // navigation.

[alexmos, 2015/09/02 21:42:09]

It sounds like taking effect on next navigation is not actually desired, but it
keeps us consistent with Blink's behavior today.  Is that correct?  Should we
add a note or TODO about that here?

[lazyboy, 2015/09/15 19:30:56]

Added TODO.

+  blink::WebFrameOwnerProperties frame_owner_properties_;
+
   // Used to track this node's loading progress (from 0 to 1).
   double loading_progress_;