Add new NSPasteboard utility function and tests.

ui/base/clipboard/clipboard_util_mac.mm

+// Copyright 2016 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 "ui/base/clipboard/clipboard_util_mac.h"
+
+#include "base/mac/scoped_cftyperef.h"
+
+namespace {
+NSString* const kWebURLsWithTitlesPboardType = @"WebURLsWithTitlesPboardType";
+NSString* const kCorePasteboardFlavorType_url =
+    @"CorePasteboardFlavorType 0x75726C20";  // 'url '  url
+NSString* const kCorePasteboardFlavorType_urln =
+    @"CorePasteboardFlavorType 0x75726C6E";  // 'urln'  title
+
+// It's much more convenient to return an NSString than a
+// base::ScopedCFTypeRef<CFStringRef>, since the methods on NSPasteboardItem
+// require an NSString*.
+NSString* UTIFromPboardType(NSString* type) {
+  return [static_cast<NSString*>(UTTypeCreatePreferredIdentifierForTag(

[Avi (use Gerrit), 2016/03/19 01:15:20]

base::mac::CFToNSCast?

[erikchen, 2016/03/21 18:26:38]

Done.

+      kUTTagClassNSPboardType, static_cast<CFStringRef>(type), kUTTypeData))

[Avi (use Gerrit), 2016/03/19 01:15:20]

base::mac::NSToCFCast?

Also, why specify conformance with kUTTypeData? Why not just say null there and
not worry?

[erikchen, 2016/03/21 18:26:38]

Done.

According to SO, we shouldn't pass null. This works, and I didn't want to spend
time figuring out whether there were weird edge cases where null doesn't work.
http://stackoverflow.com/questions/3259807/why-doesnt-nspasteboards-types-ret...

+      autorelease];

[Avi (use Gerrit), 2016/03/19 01:15:20]

And technically speaking you should use
base::mac::CFTypeRefToNSObjectAutorelease but that's borderline obsolete now so
I don't really mind either way.

[erikchen, 2016/03/21 18:26:38]

I kept -autorelease.

+}
+}  // namespace
+
+namespace ui {
+
+// static
+base::scoped_nsobject<NSPasteboardItem> ClipboardUtil::PasteboardItemFromUrl(
+    NSString* urlString,
+    NSString* title) {
+  DCHECK(urlString);
+  if (!title)
+    title = urlString;
+
+  base::scoped_nsobject<NSPasteboardItem> item([[NSPasteboardItem alloc] init]);
+
+  NSURL* url = [NSURL URLWithString:urlString];
+  if ([url isFileURL] &&
+      [[NSFileManager defaultManager] fileExistsAtPath:[url path]]) {
+    [item setPropertyList:@[ [url path] ]
+                  forType:UTIFromPboardType(NSFilenamesPboardType)];
+  }
+
+  // Set Safari's URL + title arrays Pboard type.
+  NSArray* urlsAndTitles = @[ @[ urlString ], @[ title ] ];
+  [item setPropertyList:urlsAndTitles
+                forType:UTIFromPboardType(kWebURLsWithTitlesPboardType)];
+
+  // Set NSURLPboardType.
+  NSURL *base = [url baseURL];

[Avi (use Gerrit), 2016/03/19 01:15:20]

space after *

[erikchen, 2016/03/21 18:26:38]

Done.

+  if (base) {
+    [item setPropertyList:@[ [url relativeString], [base absoluteString] ]
+                  forType:UTIFromPboardType(NSURLPboardType)];
+  } else if (url) {
+    [item setPropertyList:@[ [url absoluteString], @"" ]
+                  forType:UTIFromPboardType(NSURLPboardType)];
+  }

[Avi (use Gerrit), 2016/03/19 01:15:20]

Can you provide documentation or a link about why this split between relative
and absolute and base url for NSURLPboardType?

[erikchen, 2016/03/21 18:26:38]

Done.

The format of the property list come straight from WebKit.

+
+  [item setString:urlString forType:UTIFromPboardType(NSStringPboardType)];
+
+  const char* tempCString = [urlString UTF8String];
+  [item setData:[NSData dataWithBytes:tempCString length:strlen(tempCString)]

[Avi (use Gerrit), 2016/03/19 01:15:20]

Why not do [urlString dataUsingEncoding:NSUTF8StringEncoding]?

[erikchen, 2016/03/21 18:26:38]

I was copy-pasting from the old Mozilla code. I changed the code to use your
suggestion.

+         forType:UTIFromPboardType(kCorePasteboardFlavorType_url)];

[Avi (use Gerrit), 2016/03/19 01:15:20]

indent one fewer to align colons

[erikchen, 2016/03/21 18:26:38]

Done.

+
+  tempCString = [title UTF8String];
+  [item setData:[NSData dataWithBytes:tempCString length:strlen(tempCString)]

[Avi (use Gerrit), 2016/03/19 01:15:20]

[title dataUsingEncoding:NSUTF8StringEncoding]?

[erikchen, 2016/03/21 18:26:38]

Done.

+         forType:UTIFromPboardType(kCorePasteboardFlavorType_urln)];

[Avi (use Gerrit), 2016/03/19 01:15:20]

indent one fewer, align on :

[erikchen, 2016/03/21 18:26:38]

Done.

+  return item;
+}
+
+}  // namespace ui