Update AutocompleteTextFieldEditor to use non-deprecated dragging APIs.

chrome/browser/ui/cocoa/location_bar/autocomplete_text_field_editor.mm

 // Copyright (c) 2011 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.
 
 #import "chrome/browser/ui/cocoa/location_bar/autocomplete_text_field_editor.h"
 
 #include "base/strings/string_util.h"
 #include "base/strings/sys_string_conversions.h"
 #include "chrome/app/chrome_command_ids.h"  // IDC_*
 #include "chrome/browser/themes/theme_service.h"
 #include "chrome/browser/ui/browser_list.h"
 #import "chrome/browser/ui/cocoa/browser_window_controller.h"
 #import "chrome/browser/ui/cocoa/location_bar/autocomplete_text_field.h"
 #import "chrome/browser/ui/cocoa/location_bar/autocomplete_text_field_cell.h"
 #import "chrome/browser/ui/cocoa/toolbar/toolbar_controller.h"
 #include "chrome/grit/generated_resources.h"
 #import "ui/base/cocoa/find_pasteboard.h"
 #include "ui/base/l10n/l10n_util_mac.h"
 #include "ui/base/material_design/material_design_controller.h"
 
+@interface NSView (MountainLionSDK)
+- (BOOL)dragSelectionWithEvent:(NSEvent*)event
+                        offset:(NSSize)mouseOffset
+                     slideBack:(BOOL)slideBack;
+@end
+
 namespace {
 
+// Set to true when an instance of this class is running a nested run loop.

[Mark Mentovai, 2016/03/30 19:59:08]

Add a few words on why it’s desirable for this to be global instead of
per-instance.

[erikchen, 2016/03/30 20:05:29]

Done:

"""
30 // Since this must always be run on the UI thread, there should never be two
  31 // simultaneous drags.
"""

+bool gInDrag = false;
+
 // When too much data is put into a single-line text field, things get
 // janky due to the cost of computing the blink rect.  Sometimes users
 // accidentally paste large amounts, so place a limit on what will be
 // accepted.
 //
 // 10k characters was arbitrarily chosen by seeing how much a text
 // field could handle in a single line before it started getting too
 // janky to recover from (jankiness was detectable around 5k).
 // www.google.com returns an error for searches around 2k characters,
 // so this is conservative.
 const NSUInteger kMaxPasteLength = 10000;
 
 // Returns |YES| if too much text would be pasted.
 BOOL ThePasteboardIsTooDamnBig() {
   NSPasteboard* pb = [NSPasteboard generalPasteboard];
   NSString* type =
       [pb availableTypeFromArray:[NSArray arrayWithObject:NSStringPboardType]];
   if (!type)
     return NO;
 
   return [[pb stringForType:type] length] > kMaxPasteLength;
 }
 
 }  // namespace
 
+@interface AutocompleteTextFieldEditor ()<NSDraggingSource>
+@end
+
 @implementation AutocompleteTextFieldEditor
 
 - (BOOL)shouldDrawInsertionPoint {
   return [super shouldDrawInsertionPoint] &&
          ![[[self delegate] cell] hideFocusState];
 }
 
 - (id)initWithFrame:(NSRect)frameRect {
   if ((self = [super initWithFrame:frameRect])) {
     dropHandler_.reset([[URLDropTargetHandler alloc] initWithView:self]);
@@ skipping 39 matching lines @@
 // If the entire field is selected, drag the same data as would be
 // dragged from the field's location icon.  In some cases the textual
 // contents will not contain relevant data (for instance, "http://" is
 // stripped from URLs).
 - (BOOL)dragSelectionWithEvent:(NSEvent *)event
                         offset:(NSSize)mouseOffset
                      slideBack:(BOOL)slideBack {
   AutocompleteTextFieldObserver* observer = [self observer];
   DCHECK(observer);
   if (observer && observer->CanCopy()) {
-    NSPasteboard* pboard = [NSPasteboard pasteboardWithName:NSDragPboard];
-    observer->CopyToPasteboard(pboard);
-
     NSPoint p;
     NSImage* image = [self dragImageForSelectionWithEvent:event origin:&p];
 
-    [self dragImage:image
-                 at:p
-             offset:mouseOffset
-              event:event
-         pasteboard:pboard
-             source:self
-          slideBack:slideBack];
+    base::scoped_nsobject<NSPasteboardItem> item(
+        observer->CreatePasteboardItem());
+    base::scoped_nsobject<NSDraggingItem> dragItem(
+        [[NSDraggingItem alloc] initWithPasteboardWriter:item]);
+    [dragItem setDraggingFrame:[self bounds] contents:image];
+    [self beginDraggingSessionWithItems:@[ dragItem.get() ]
+                                  event:event
+                                 source:self];
+    gInDrag = true;

[Mark Mentovai, 2016/03/30 19:59:08]

DCHECK(!gInDrag);

[erikchen, 2016/03/30 20:05:29]

Done.

+    while (gInDrag) {
+      [[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode
+                               beforeDate:[NSDate distantFuture]];
+    }
+
     return YES;
   }
   return [super dragSelectionWithEvent:event
                                 offset:mouseOffset
                              slideBack:slideBack];
 }
 
+- (void)draggingSession:(NSDraggingSession*)session
+           endedAtPoint:(NSPoint)aPoint
+              operation:(NSDragOperation)operation {
+  gInDrag = false;
+}
+
 - (void)copy:(id)sender {
   AutocompleteTextFieldObserver* observer = [self observer];
   DCHECK(observer);
   if (observer && observer->CanCopy())
     observer->CopyToPasteboard([NSPasteboard generalPasteboard]);
 }
 
 - (void)cut:(id)sender {
   [self copy:sender];
   [self delete:nil];
@@ skipping 427 matching lines @@
       [[self delegate] suggestText],
       [[self delegate] suggestColor],
       self,
       [self bounds]);
   AutocompleteTextFieldObserver* observer = [self observer];
   if (observer)
     observer->OnDidDrawRect();
 }
 
 @end