platform_util::OpenItem fixes

chrome/browser/platform_util_mac.mm

Index: chrome/browser/platform_util_mac.mm
===================================================================
--- chrome/browser/platform_util_mac.mm	(revision 108523)
+++ chrome/browser/platform_util_mac.mm	(working copy)
@@ -20,7 +20,7 @@
 namespace platform_util {
 
 void ShowItemInFolder(const FilePath& full_path) {
-  DCHECK_EQ([NSThread currentThread], [NSThread mainThread]);
+  DCHECK([NSThread isMainThread]);
   NSString* path_string = base::SysUTF8ToNSString(full_path.value());
   if (!path_string || ![[NSWorkspace sharedWorkspace] selectFile:path_string
                                         inFileViewerRootedAtPath:nil])
@@ -35,7 +35,7 @@
 // Instead, an AppleEvent is constructed to tell the Finder to open the
 // document.
 void OpenItem(const FilePath& full_path) {

[Randy Smith (Not in Mondays), 2011/11/08 22:27:55]

So my interpretation of what I'm reading is that we're now counting on OpenItem
to always be called on the UI thread (some implementations redirect, but this
one doesn't, so the interface restriction is that we always call on the UI
thread).  If that's the case, can we update the commentary in platform_util.h to
say so?

[achuithb, 2011/11/09 00:26:27]

Done.

-  DCHECK_EQ([NSThread currentThread], [NSThread mainThread]);
+  DCHECK([NSThread isMainThread]);
   NSString* path_string = base::SysUTF8ToNSString(full_path.value());
   if (!path_string)
     return;
@@ -121,7 +121,7 @@
 }
 
 void OpenExternal(const GURL& url) {
-  DCHECK_EQ([NSThread currentThread], [NSThread mainThread]);
+  DCHECK([NSThread isMainThread]);
   NSString* url_string = base::SysUTF8ToNSString(url.spec());
   NSURL* ns_url = [NSURL URLWithString:url_string];
   if (!ns_url || ![[NSWorkspace sharedWorkspace] openURL:ns_url])