[Mac] On Mavericks or later, use NSWorkspace to open download items.

With the NSWorkspaceLaunchWithErrorPresentation option, Finder no longer
silently fails opening the file.

BUG=32921
R=avi@chromium.org
TEST=Download a DMG file. Click the download shelf button to open/mount it. Finder activates the new disk image window as the topmost.
TEST=Download a file with an unassociated file extension type (e.g.  "test.foobar"). Click the download shelf button to open it. Finder presents the unknown file type dialog.

Review URL: https://codereview.chromium.org/613673003

Cr-Commit-Position: refs/heads/master@{#297239}

base/mac/sdk_forward_declarations.h

@@ -285,6 +285,10 @@ typedef NSUInteger NSWindowOcclusionState;
 - (NSWindowOcclusionState)occlusionState;
 @end
 
+enum {
+  NSWorkspaceLaunchWithErrorPresentation = 0x00000040
+};
+
 #else  // !MAC_OS_X_VERSION_10_9
 
 typedef enum {

chrome/browser/platform_util_mac.mm

@@ -11,6 +11,8 @@
 #include "base/files/file_path.h"
 #include "base/logging.h"
 #include "base/mac/mac_logging.h"
+#import "base/mac/mac_util.h"
+#import "base/mac/sdk_forward_declarations.h"
 #include "base/mac/scoped_aedesc.h"
 #include "base/strings/sys_string_conversions.h"
 #include "url/gurl.h"
@@ -25,19 +27,35 @@ void ShowItemInFolder(Profile* profile, const base::FilePath& full_path) {
     LOG(WARNING) << "NSWorkspace failed to select file " << full_path.value();
 }
 
-// This function opens a file.  This doesn't use LaunchServices or NSWorkspace
-// because of two bugs:
-//  1. Incorrect app activation with com.apple.quarantine:
-//     http://crbug.com/32921
-//  2. Silent no-op for unassociated file types: http://crbug.com/50263
-// Instead, an AppleEvent is constructed to tell the Finder to open the
-// document.
 void OpenItem(Profile* profile, const base::FilePath& full_path) {
   DCHECK([NSThread isMainThread]);
   NSString* path_string = base::SysUTF8ToNSString(full_path.value());
   if (!path_string)
     return;
 
+  // On Mavericks or later, NSWorkspaceLaunchWithErrorPresentation will
+  // properly handle Finder activation for quarantined files
+  // (http://crbug.com/32921) and unassociated file types
+  // (http://crbug.com/50263).
+  if (base::mac::IsOSMavericksOrLater()) {
+    NSURL* url = [NSURL fileURLWithPath:path_string];
+    if (!url)
+      return;
+
+    const NSWorkspaceLaunchOptions launch_options =
+        NSWorkspaceLaunchAsync | NSWorkspaceLaunchWithErrorPresentation;
+    [[NSWorkspace sharedWorkspace] openURLs:@[ url ]
+                    withAppBundleIdentifier:nil
+                                    options:launch_options
+             additionalEventParamDescriptor:nil
+                          launchIdentifiers:NULL];
+    return;
+  }
+
+  // On older OSes, both LaunchServices and NSWorkspace will fail silently for
+  // the two cases described above. On those platforms, use an AppleEvent to
+  // instruct the Finder to open the file.
+
   // Create the target of this AppleEvent, the Finder.
   base::mac::ScopedAEDesc<AEAddressDesc> address;
   const OSType finderCreatorCode = 'MACS';