Revert of mac: History swiping doesn't work right with iframes.

content/browser/renderer_host/render_widget_host_view_mac.mm

Index: content/browser/renderer_host/render_widget_host_view_mac.mm
diff --git a/content/browser/renderer_host/render_widget_host_view_mac.mm b/content/browser/renderer_host/render_widget_host_view_mac.mm
index 5dffd123e1333e6ddaebc5d3e37295243367b2da..997e63d3ade77cb0465cc26067724d271a22dad0 100644
--- a/content/browser/renderer_host/render_widget_host_view_mac.mm
+++ b/content/browser/renderer_host/render_widget_host_view_mac.mm
@@ -143,7 +143,9 @@
 
 + (BOOL)shouldAutohideCursorForEvent:(NSEvent*)event;
 - (id)initWithRenderWidgetHostViewMac:(RenderWidgetHostViewMac*)r;
-- (void)gotWheelEventConsumed:(BOOL)consumed;
+- (void)gotUnhandledWheelEvent;
+- (void)scrollOffsetPinnedToLeft:(BOOL)left toRight:(BOOL)right;
+- (void)setHasHorizontalScrollbar:(BOOL)has_horizontal_scrollbar;
 - (void)keyEvent:(NSEvent*)theEvent wasKeyEquivalent:(BOOL)equiv;
 - (void)windowDidChangeBackingProperties:(NSNotification*)notification;
 - (void)windowChangedGlobalFrame:(NSNotification*)notification;
@@ -1860,10 +1862,13 @@
 
 void RenderWidgetHostViewMac::SetHasHorizontalScrollbar(
     bool has_horizontal_scrollbar) {
+  [cocoa_view_ setHasHorizontalScrollbar:has_horizontal_scrollbar];
 }
 
 void RenderWidgetHostViewMac::SetScrollOffsetPinning(
     bool is_pinned_to_left, bool is_pinned_to_right) {
+  [cocoa_view_ scrollOffsetPinnedToLeft:is_pinned_to_left
+                                toRight:is_pinned_to_right];
 }
 
 bool RenderWidgetHostViewMac::LockMouse() {
@@ -1895,11 +1900,12 @@
     render_widget_host_->LostMouseLock();
 }
 
-void RenderWidgetHostViewMac::HandledWheelEvent(
-    const blink::WebMouseWheelEvent& event,
-    bool consumed) {
+void RenderWidgetHostViewMac::UnhandledWheelEvent(
+    const blink::WebMouseWheelEvent& event) {
+  // Only record a wheel event as unhandled if JavaScript handlers got a chance
+  // to see it (no-op wheel events are ignored by the event dispatcher)
   if (event.deltaX || event.deltaY)
-    [cocoa_view_ gotWheelEventConsumed:consumed];
+    [cocoa_view_ gotUnhandledWheelEvent];
 }
 
 bool RenderWidgetHostViewMac::Send(IPC::Message* message) {
@@ -2358,8 +2364,28 @@
   }
 }
 
-- (void)gotWheelEventConsumed:(BOOL)consumed {
-  [responderDelegate_ gotWheelEventConsumed:consumed];
+- (void)gotUnhandledWheelEvent {
+  if (responderDelegate_ &&
+      [responderDelegate_
+          respondsToSelector:@selector(gotUnhandledWheelEvent)]) {
+    [responderDelegate_ gotUnhandledWheelEvent];
+  }
+}
+
+- (void)scrollOffsetPinnedToLeft:(BOOL)left toRight:(BOOL)right {
+  if (responderDelegate_ &&
+      [responderDelegate_
+          respondsToSelector:@selector(scrollOffsetPinnedToLeft:toRight:)]) {
+    [responderDelegate_ scrollOffsetPinnedToLeft:left toRight:right];
+  }
+}
+
+- (void)setHasHorizontalScrollbar:(BOOL)has_horizontal_scrollbar {
+  if (responderDelegate_ &&
+      [responderDelegate_
+          respondsToSelector:@selector(setHasHorizontalScrollbar:)]) {
+    [responderDelegate_ setHasHorizontalScrollbar:has_horizontal_scrollbar];
+  }
 }
 
 - (BOOL)respondsToSelector:(SEL)selector {