Revert of Add a dead zone when dragging tabs horizontally on Mac

chrome/browser/ui/cocoa/tabs/tab_strip_drag_controller.mm

Index: chrome/browser/ui/cocoa/tabs/tab_strip_drag_controller.mm
diff --git a/chrome/browser/ui/cocoa/tabs/tab_strip_drag_controller.mm b/chrome/browser/ui/cocoa/tabs/tab_strip_drag_controller.mm
index 074476a276614c9312140774a33caf325561f25b..3d168310cbb5820ab90d3ccf9d4b9e060d6e76ba 100644
--- a/chrome/browser/ui/cocoa/tabs/tab_strip_drag_controller.mm
+++ b/chrome/browser/ui/cocoa/tabs/tab_strip_drag_controller.mm
@@ -17,7 +17,6 @@
 #include "ui/base/cocoa/cocoa_base_utils.h"
 #include "ui/gfx/mac/scoped_cocoa_disable_screen_updates.h"
 
-const CGFloat kHorizontalTearDistance = 10.0; // Using the same value as Views.
 const CGFloat kTearDistance = 36.0;
 const NSTimeInterval kTearDuration = 0.333;
 
@@ -172,17 +171,9 @@
   if (draggingWithinTabStrip_) {
     NSPoint thisPoint = [NSEvent mouseLocation];
     CGFloat offset = thisPoint.x - dragOrigin_.x;
-    // Only begin dragging the tab horizontally if it's torn out of its dead
-    // zone.
-    if (!outOfTabHorizontalDeadZone_ &&
-        fabs(offset) > kHorizontalTearDistance) {
-      outOfTabHorizontalDeadZone_ = YES;
-    }
-    if (outOfTabHorizontalDeadZone_) {
-      [sourceController_ insertPlaceholderForTab:[draggedTab_ tabView]
-                                           frame:NSOffsetRect(sourceTabFrame_,
-                                                              offset, 0)];
-    }
+    [sourceController_ insertPlaceholderForTab:[draggedTab_ tabView]
+                                         frame:NSOffsetRect(sourceTabFrame_,
+                                                            offset, 0)];
     // Check that we haven't pulled the tab too far to start a drag. This
     // can include either pulling it too far down, or off the side of the tab
     // strip that would cause it to no longer be fully visible.
@@ -412,7 +403,6 @@
 - (void)endDrag:(NSEvent*)event {
   // Cancel any delayed -continueDrag: requests that may still be pending.
   [NSObject cancelPreviousPerformRequestsWithTarget:self];
-  outOfTabHorizontalDeadZone_ = NO;
 
   // Special-case this to keep the logic below simpler.
   if (moveWindowOnDrag_) {