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

chrome/browser/renderer_host/chrome_render_widget_host_view_mac_history_swiper.mm

Index: chrome/browser/renderer_host/chrome_render_widget_host_view_mac_history_swiper.mm
diff --git a/chrome/browser/renderer_host/chrome_render_widget_host_view_mac_history_swiper.mm b/chrome/browser/renderer_host/chrome_render_widget_host_view_mac_history_swiper.mm
index 8cf35cdf9a4a828002a8d9f3126f82719567fef8..47f795edf3d55dcf6cecc0e88c1599affdcd062e 100644
--- a/chrome/browser/renderer_host/chrome_render_widget_host_view_mac_history_swiper.mm
+++ b/chrome/browser/renderer_host/chrome_render_widget_host_view_mac_history_swiper.mm
@@ -43,12 +43,17 @@
   return NO;
 }
 
-- (void)gotWheelEventConsumed:(BOOL)consumed {
-  if (consumed) {
-    gestureHandledState_ = history_swiper::kHandled;
-  } else if (gestureHandledState_ == history_swiper::kPending) {
-    gestureHandledState_ = history_swiper::kUnhandled;
-  }
+- (void)gotUnhandledWheelEvent {
+  gotUnhandledWheelEvent_ = YES;
+}
+
+- (void)scrollOffsetPinnedToLeft:(BOOL)left toRight:(BOOL)right {
+  isPinnedLeft_ = left;
+  isPinnedRight_ = right;
+}
+
+- (void)setHasHorizontalScrollbar:(BOOL)hasHorizontalScrollbar {
+  hasHorizontalScrollbar_ = hasHorizontalScrollbar;
 }
 
 - (BOOL)canRubberbandLeft:(NSView*)view {
@@ -88,7 +93,7 @@
   // Reset state pertaining to previous gestures.
   historySwipeCancelled_ = NO;
   gestureStartPointValid_ = NO;
-  gestureHandledState_ = history_swiper::kPending;
+  gotUnhandledWheelEvent_ = NO;
   receivedTouch_ = NO;
   mouseScrollDelta_ = NSZeroSize;
 }
@@ -337,6 +342,14 @@
       [self browserCanNavigateInDirection:direction event:theEvent];
   if (!browserCanMove)
     return NO;
+
+  if (isRightScroll) {
+    if (hasHorizontalScrollbar_ && !isPinnedRight_)
+      return NO;
+  } else {
+    if (hasHorizontalScrollbar_ && !isPinnedLeft_)
+      return NO;
+  }
 
   [self initiateMagicMouseHistorySwipe:isRightScroll event:theEvent];
   return YES;
@@ -474,9 +487,9 @@
   if (![delegate_ shouldAllowHistorySwiping])
     return NO;
 
-  // Only enable history swiping if blink has never handled any of the events in
-  // the gesture.
-  if (gestureHandledState_ != history_swiper::kUnhandled)
+  // Don't even consider enabling history swiping until blink has decided it is
+  // not going to handle the event.
+  if (!gotUnhandledWheelEvent_)
     return NO;
 
   // If the window has a horizontal scroll bar, sometimes Cocoa gets confused
@@ -512,6 +525,14 @@
   if (inverted)
     isRightScroll = !isRightScroll;
 
+  if (isRightScroll) {
+    if (hasHorizontalScrollbar_ && !isPinnedRight_)
+      return NO;
+  } else {
+    if (hasHorizontalScrollbar_ && !isPinnedLeft_)
+      return NO;
+  }
+
   history_swiper::NavigationDirection direction =
       isRightScroll ? history_swiper::kForwards : history_swiper::kBackwards;
   BOOL browserCanMove =