Extract Favicon Download logic from FaviconTabHelper

chrome/browser/favicon/DEPS

 include_rules = [
   # Favicon is being made into a Browser Component, so we have these
   # three basic rules followed by temporary exceptions.  Please don't
   # add to the list of exceptions!
   "-chrome/browser",
   "+chrome/browser/api",
   "+chrome/browser/common",
   "+chrome/browser/favicon",
 
   # Permanently-allowed DEPS beyond the standard Browser
@@ skipping 13 matching lines @@
   "!chrome/browser/history/select_favicon_frames.h",
   "!chrome/browser/prefs/pref_service.h",
   "!chrome/browser/profiles/profile.h",
   "!chrome/browser/profiles/profile_dependency_manager.h",
   "!chrome/browser/profiles/profile_keyed_service.h",
   "!chrome/browser/profiles/profile_keyed_service_factory.h",
   "!chrome/browser/ui/webui/chrome_web_ui_controller_factory.h",
   # Do not add to the list of temporarily-allowed dependencies above,
   # and please do not introduce more #includes of these files.
 ]
+
+specific_include_rules = {
+  # TODO(caitkp): Look into removing history/ dependencies.
+  'favicon_download_helper(_delegate)*\.(h|cc)': [
+    "-chrome",
+    "-chrome/browser",
+    "+chrome/browser/favicon",

[Jói, 2012/10/18 15:04:46]

You probably don't want to allow all of chrome/browser/favicon since some of
them may transitively include the rest of the world.  Same thing below I think.

+    "+chrome/common/icon_messages.h",
+  ],
+
+  'favicon_util\.(h|cc)': [
+    "-chrome",
+    "-chrome/browser",
+    "+chrome/browser/favicon",
+    "+chrome/common/icon_messages.h",
+    "!chrome/browser/history/history_types.h",
+    "!chrome/browser/history/select_favicon_frames.h",
+  ]
+}