Removing base::ThreadRestrictions::ScopedAllowIO from icon_manager_linux.cc

chrome/browser/icon_loader_mac.mm

Index: chrome/browser/icon_loader_mac.mm
diff --git a/chrome/browser/icon_loader_mac.mm b/chrome/browser/icon_loader_mac.mm
index 7f522b17b75a9e5e94752ff43a6d05e19395b972..500762ec47ed4f9f7f4506a652b81ac143559d53 100644
--- a/chrome/browser/icon_loader_mac.mm
+++ b/chrome/browser/icon_loader_mac.mm
@@ -7,12 +7,18 @@
 #import <AppKit/AppKit.h>
 
 #include "base/bind.h"
+#include "base/file_path.h"
 #include "base/message_loop.h"
 #include "base/threading/thread.h"
 #include "base/sys_string_conversions.h"
 #include "ui/gfx/image/image_skia.h"
 #include "ui/gfx/image/image_skia_util_mac.h"
 
+IconGroupID IconManager::ReadGroupIDFromFilepath(
+    const base::FilePath& filepath) {
+  return filepath.Extension();
+}
+
 void IconLoader::ReadIcon() {
   NSString* group = base::SysUTF8ToNSString(group_);
   NSWorkspace* workspace = [NSWorkspace sharedWorkspace];