mac: Only let two-finger-scrolling trigger history if web doesn't swallow gesture

content/browser/renderer_host/render_view_host.cc

Index: content/browser/renderer_host/render_view_host.cc
diff --git a/content/browser/renderer_host/render_view_host.cc b/content/browser/renderer_host/render_view_host.cc
index 8af8ed86594def723ee00d433fbcddfe258a6ab8..463ad36b0fcce5661008cfea7ebbb6b8a5a6c776 100644
--- a/content/browser/renderer_host/render_view_host.cc
+++ b/content/browser/renderer_host/render_view_host.cc
@@ -1009,16 +1009,17 @@ void RenderViewHost::OnMsgDidContentsPreferredSizeChange(
 
 void RenderViewHost::OnMsgDidChangeScrollbarsForMainFrame(
     bool has_horizontal_scrollbar, bool has_vertical_scrollbar) {
-  // TODO(thakis): Implement, http://crbug.com/90228
+  if (view())
+    view()->SetHasHorizontalScrollbar(has_horizontal_scrollbar);
 }
 
 void RenderViewHost::OnMsgDidChangeScrollOffsetPinningForMainFrame(
     bool is_pinned_to_left, bool is_pinned_to_right) {
-  // TODO(thakis): Implement, http://crbug.com/90228
+  if (view())
+    view()->SetScrollOffsetPinning(is_pinned_to_left, is_pinned_to_right);
 }
 
 void RenderViewHost::OnMsgDidChangeNumWheelEvents(int count) {

[Mark Mentovai, 2011/08/15 14:43:57]

Will we be using this at all?

[Nico, 2011/08/15 16:39:46]

Good question. WebKit2 piped it through along with the two other values, so
"maybe". I notice that they somehow manage to not wait for unhandled scrolls
from the renderer right after page load (you can swipe through many pages very
quickly in Safari, while we currently have to wait for every page to load enough
that the renderer can return a swipe event). So maybe I'll need it for that
soon. If it turns out I won't need it, I'll remove the plumbing for this again.

-  // TODO(thakis): Implement, http://crbug.com/90228
 }
 
 void RenderViewHost::OnMsgSelectionChanged(const std::string& text,