Fix "unreachable code" warnings (MSVC warning 4702) in chrome/browser/.

chrome/browser/ui/views/tabs/tab_drag_controller.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/views/tabs/tab_drag_controller.h"
 
 #include <math.h>
 #include <set>
 
 #include "base/auto_reset.h"
@@ skipping 78 matching lines @@
 #endif
 }
 
 // Returns true if |tab_strip| browser window is docked.
 bool IsDockedOrSnapped(const TabStrip* tab_strip) {
 #if defined(USE_ASH)
   DCHECK(tab_strip);
   ash::wm::WindowState* window_state =
       ash::wm::GetWindowState(tab_strip->GetWidget()->GetNativeWindow());
   return window_state->IsDocked() || window_state->IsSnapped();
+#else
+  return false;
 #endif
-  return false;
 }
 
 // Returns true if |bounds| contains the y-coordinate |y|. The y-coordinate
 // of |bounds| is adjusted by |vertical_adjustment|.
 bool DoesRectContainVerticalPointExpanded(
     const gfx::Rect& bounds,
     int vertical_adjustment,
     int y) {
   int upper_threshold = bounds.bottom() + vertical_adjustment;
   int lower_threshold = bounds.y() - vertical_adjustment;
@@ skipping 1795 matching lines @@
     aura::Window* dragged_window =
         attached_tabstrip_->GetWidget()->GetNativeView();
     if (dragged_window)
       exclude.insert(dragged_window);
   }
   return GetLocalProcessWindowAtPoint(host_desktop_type_,
                                       screen_point,
                                       exclude);
 
 }