[Reland] Fix crash when accidentally touching the screen during a multi window resize

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 419 matching lines @@
   // Need to delete the view here manually _before_ we reset the dragged
   // contents to NULL, otherwise if the view is animating to its destination
   // bounds, it won't be able to clean up properly since its cleanup routine
   // uses GetIndexForDraggedContents, which will be invalid.
   view_.reset(NULL);
 
   // Reset the delegate of the dragged WebContents. This ends up doing nothing
   // if the drag was completed.
   if (!detach_into_browser_)
     ResetDelegates();
+
+  if (event_source_ == EVENT_SOURCE_TOUCH) {
+    TabStrip* capture_tabstrip = (attached_tabstrip_ && detach_into_browser_) ?
+        attached_tabstrip_ : source_tabstrip_;
+    capture_tabstrip->GetWidget()->ReleaseCapture();
+  }
 }
 
 void TabDragController::Init(
     TabStrip* source_tabstrip,
     Tab* source_tab,
     const std::vector<Tab*>& tabs,
     const gfx::Point& mouse_offset,
     int source_tab_offset,
     const ui::ListSelectionModel& initial_selection_model,
     DetachBehavior detach_behavior,
@@ skipping 32 matching lines @@
   // Listen for Esc key presses.
   base::MessageLoopForUI::current()->AddObserver(this);
 
   if (source_tab->width() > 0) {
     offset_to_width_ratio_ = static_cast<float>(
         source_tab->GetMirroredXInView(source_tab_offset)) /
         static_cast<float>(source_tab->width());
   }
   InitWindowCreatePoint();
   initial_selection_model_.Copy(initial_selection_model);
+
+  // Gestures don't automatically do a capture. We don't allow multiple drags at
+  // the same time, so we explicitly capture.
+  if (event_source == EVENT_SOURCE_TOUCH)
+    source_tabstrip_->GetWidget()->SetCapture(source_tabstrip_);
 }
 
 // static
 bool TabDragController::IsAttachedTo(const TabStrip* tab_strip) {
   return (instance_ && instance_->active() &&
           instance_->attached_tabstrip() == tab_strip);
 }
 
 // static
 bool TabDragController::IsActive() {
@@ skipping 1818 matching lines @@
 gfx::Vector2d TabDragController::GetWindowOffset(
     const gfx::Point& point_in_screen) {
   TabStrip* owning_tabstrip = (attached_tabstrip_ && detach_into_browser_) ?
       attached_tabstrip_ : source_tabstrip_;
   views::View* toplevel_view = owning_tabstrip->GetWidget()->GetContentsView();
 
   gfx::Point point = point_in_screen;
   views::View::ConvertPointFromScreen(toplevel_view, &point);
   return point.OffsetFromOrigin();
 }