stub impl of linux,mac icon loader/manager

chrome/chrome.gyp

Index: chrome/chrome.gyp
===================================================================
--- chrome/chrome.gyp	(revision 15577)
+++ chrome/chrome.gyp	(working copy)
@@ -960,10 +960,14 @@
         'browser/history/visitsegment_database.h',
         'browser/hung_renderer_dialog.h',
         'browser/icon_loader.h',
+        'browser/icon_loader_linux.cc',
+        'browser/icon_loader_mac.mm',
         'browser/icon_loader_win.cc',
-        'browser/icon_loader_win.h',
         'browser/icon_manager.cc',
         'browser/icon_manager.h',
+        'browser/icon_manager_linux.cc',
+        'browser/icon_manager_mac.mm',
+        'browser/icon_manager_win.cc',
         'browser/ime_input.cc',
         'browser/ime_input.h',
         'browser/importer/firefox2_importer.cc',
@@ -1496,6 +1500,7 @@
             'browser/bookmarks/bookmark_context_menu.cc',
             'browser/bookmarks/bookmark_drop_info.cc',
             'browser/debugger/debugger_shell_stubs.cc',
+            'browser/icon_manager.cc',
           ],
           'sources': [
             # Build the necessary GTM sources
@@ -1580,7 +1585,6 @@
             'browser/history/history_indexer.idl',
             'browser/history_tab_ui.cc',
             'browser/history_view.cc',
-            'browser/icon_manager.cc',
             'browser/ime_input.cc',
             'browser/importer/ie_importer.cc',
             'browser/jankometer.cc',