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

chrome/browser/ui/cocoa/browser_window_controller.mm

Index: chrome/browser/ui/cocoa/browser_window_controller.mm
diff --git a/chrome/browser/ui/cocoa/browser_window_controller.mm b/chrome/browser/ui/cocoa/browser_window_controller.mm
index 024760945c4c7d6c0238c8d770ee008cb35b87cc..3c89b2cb7062022ee9a88075c5e9f6defdf8fc4f 100644
--- a/chrome/browser/ui/cocoa/browser_window_controller.mm
+++ b/chrome/browser/ui/cocoa/browser_window_controller.mm
@@ -43,7 +43,6 @@
 #import "chrome/browser/ui/cocoa/find_bar/find_bar_cocoa_controller.h"
 #import "chrome/browser/ui/cocoa/framed_browser_window.h"
 #import "chrome/browser/ui/cocoa/fullscreen_window.h"
-#import "chrome/browser/ui/cocoa/gesture_utils.h"
 #import "chrome/browser/ui/cocoa/image_utils.h"
 #import "chrome/browser/ui/cocoa/infobars/infobar_container_controller.h"
 #import "chrome/browser/ui/cocoa/location_bar/autocomplete_text_field_editor.h"
@@ -157,33 +156,6 @@
 
 @end
 
-// Forward-declare symbols that are part of the 10.6 SDK.
-#if !defined(MAC_OS_X_VERSION_10_6) || \
-    MAC_OS_X_VERSION_MAX_ALLOWED < MAC_OS_X_VERSION_10_6
-
-enum {
-    NSTouchPhaseBegan           = 1U << 0,
-    NSTouchPhaseMoved           = 1U << 1,
-    NSTouchPhaseStationary      = 1U << 2,
-    NSTouchPhaseEnded           = 1U << 3,
-    NSTouchPhaseCancelled       = 1U << 4,
-    NSTouchPhaseTouching        = NSTouchPhaseBegan | NSTouchPhaseMoved |
-                                  NSTouchPhaseStationary,
-    NSTouchPhaseAny             = NSUIntegerMax
-};
-typedef NSUInteger NSTouchPhase;
-
-@interface NSEvent (SnowLeopardDeclarations)
-- (NSSet*)touchesMatchingPhase:(NSTouchPhase)phase inView:(NSView*)view;
-@end
-
-@interface NSTouch : NSObject
-- (NSPoint)normalizedPosition;
-- (id<NSObject, NSCopying>)identity;
-@end
-
-#endif  // MAC_OS_X_VERSION_10_6
-
 // Provide the forward-declarations of new 10.7 SDK symbols so they can be
 // called when building with the 10.5 SDK.
 #if !defined(MAC_OS_X_VERSION_10_7) || \
@@ -1784,96 +1756,6 @@ enum {
   }
 }
 
-// Documented in 10.6+, but present starting in 10.5. Called at the beginning
-// of a gesture.
-- (void)beginGestureWithEvent:(NSEvent*)event {
-  totalMagnifyGestureAmount_ = 0;
-  currentZoomStepDelta_ = 0;
-
-  // On Lion, there's support controlled by a System Preference for two- and
-  // three-finger navigational gestures. If set to allow three-finger gestures,
-  // the system gesture recognizer will automatically call |-swipeWithEvent:|
-  // and that will be handled as it would be on Snow Leopard. The two-finger
-  // gesture does not do this, so it must be manually recognized. See the note
-  // inside RecognizeTwoFingerGestures() for detailed information on the
-  // interaction of the different preferences.
-  if (!gesture_utils::RecognizeTwoFingerGestures())
-    return;
-  NSSet* touches = [event touchesMatchingPhase:NSTouchPhaseAny
-                                        inView:nil];
-  if ([touches count] >= 2) {
-    twoFingerGestureTouches_.reset([[NSMutableDictionary alloc] init]);
-    for (NSTouch* touch in touches) {
-      [twoFingerGestureTouches_ setObject:touch forKey:touch.identity];
-    }
-  }
-}
-
-- (void)endGestureWithEvent:(NSEvent*)event {
-  // This method only needs to process gesture events for two-finger navigation.
-  if (!twoFingerGestureTouches_.get())
-    return;
-
-  // When a multi-touch gesture ends, only one touch will be in the "End" phase.
-  // Other touches will be in "Moved" or "Unknown" phases. So long as one is
-  // ended, which it is by virtue of this method being called, the gesture can
-  // be committed so long as the magnitude is great enough.
-  NSSet* touches = [event touchesMatchingPhase:NSTouchPhaseAny
-                                        inView:nil];
-
-  // Store the touch data locally and reset the ivar so that new gestures can
-  // begin.
-  scoped_nsobject<NSDictionary> beginTouches(
-      twoFingerGestureTouches_.release());
-
-  // Construct a vector of magnitudes. Since gesture events do not have the
-  // |-deltaX| property set, this creates the X/Y magnitudes for each finger.
-  std::vector<CGFloat> deltasX;
-  std::vector<CGFloat> deltasY;
-  for (NSTouch* touch in touches) {
-    NSTouch* beginTouch = [beginTouches objectForKey:touch.identity];
-    if (!beginTouch)
-      continue;
-
-    // The |normalizedPosition| is scaled from (0, 1).
-    NSPoint beginPoint = beginTouch.normalizedPosition;
-    NSPoint endPoint = touch.normalizedPosition;
-
-    deltasX.push_back(endPoint.x - beginPoint.x);
-    deltasY.push_back(endPoint.y - beginPoint.y);
-  }
-
-  // Need at least two points to gesture.
-  if (deltasX.size() < 2)
-    return;
-
-  CGFloat sumX = std::accumulate(deltasX.begin(), deltasX.end(), 0.0f);
-  CGFloat sumY = std::accumulate(deltasY.begin(), deltasY.end(), 0.0f);
-
-  // If the Y magnitude is greater than the X, then don't treat this as a
-  // gesture. It was likely a vertical scroll instead.
-  if (std::abs(sumY) > std::abs(sumX))
-    return;
-
-  // On Lion, the user can choose to use a "natural" scroll direction with
-  // inverted axes.
-  if (gesture_utils::IsScrollDirectionInverted())
-    sumX *= -1;
-
-  int command_id = 0;
-  if (sumX > 0.3)
-    command_id = IDC_FORWARD;
-  else if (sumX < -0.3)
-    command_id = IDC_BACK;
-  else
-    return;
-
-  if (browser_->command_updater()->IsCommandEnabled(command_id)) {
-    browser_->ExecuteCommandWithDisposition(command_id,
-        event_utils::WindowOpenDispositionFromNSEvent(event));
-  }
-}
-
 // Delegate method called when window is resized.
 - (void)windowDidResize:(NSNotification*)notification {
   // Resize (and possibly move) the status bubble. Note that we may get called