Update AutocompleteTextFieldEditor to use non-deprecated dragging APIs.

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

Index: chrome/browser/ui/cocoa/location_bar/autocomplete_text_field_editor.mm
diff --git a/chrome/browser/ui/cocoa/location_bar/autocomplete_text_field_editor.mm b/chrome/browser/ui/cocoa/location_bar/autocomplete_text_field_editor.mm
index 86303014acea83a5152c4932743979a40ed20563..bc0c379790b428249a9b4815eeb6df7beb30a9a9 100644
--- a/chrome/browser/ui/cocoa/location_bar/autocomplete_text_field_editor.mm
+++ b/chrome/browser/ui/cocoa/location_bar/autocomplete_text_field_editor.mm
@@ -18,8 +18,17 @@
 #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
@@ -45,6 +54,9 @@ BOOL ThePasteboardIsTooDamnBig() {
 
 }  // namespace
 
+@interface AutocompleteTextFieldEditor ()<NSDraggingSource>
+@end
+
 @implementation AutocompleteTextFieldEditor
 
 - (BOOL)shouldDrawInsertionPoint {
@@ -104,19 +116,23 @@ BOOL ThePasteboardIsTooDamnBig() {
   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
@@ -124,6 +140,12 @@ BOOL ThePasteboardIsTooDamnBig() {
                              slideBack:slideBack];
 }
 
+- (void)draggingSession:(NSDraggingSession*)session
+           endedAtPoint:(NSPoint)aPoint
+              operation:(NSDragOperation)operation {
+  gInDrag = false;
+}
+
 - (void)copy:(id)sender {
   AutocompleteTextFieldObserver* observer = [self observer];
   DCHECK(observer);