First cut at custom user style sheets.

chrome/browser/profile.cc

Index: chrome/browser/profile.cc
diff --git a/chrome/browser/profile.cc b/chrome/browser/profile.cc
index 1e248e2198a681df59a42e48ce9e9bd2f8aaf11c..c78b64a161ad36ebf578b1d30fcea46ad2dea04b 100644
--- a/chrome/browser/profile.cc
+++ b/chrome/browser/profile.cc
@@ -50,6 +50,7 @@
 #include "chrome/browser/sync/profile_sync_service.h"
 #include "chrome/browser/sync/profile_sync_factory_impl.h"
 #include "chrome/browser/thumbnail_store.h"
+#include "chrome/browser/user_style_sheet_watcher.h"
 #include "chrome/browser/visitedlink_master.h"
 #include "chrome/browser/visitedlink_event_listener.h"
 #include "chrome/browser/webdata/web_data_service.h"
@@ -410,6 +411,10 @@ class OffTheRecordProfileImpl : public Profile,
     return profile_->GetPrivacyBlacklist();
   }
 
+  virtual UserStyleSheetWatcher* GetUserStyleSheetWatcher() {
+    return profile_->GetUserStyleSheetWatcher();
+  }
+
   virtual SessionService* GetSessionService() {
     // Don't save any sessions when off the record.
     return NULL;
@@ -988,6 +993,14 @@ Blacklist* ProfileImpl::GetPrivacyBlacklist() {
   return privacy_blacklist_.get();
 }
 
+UserStyleSheetWatcher* ProfileImpl::GetUserStyleSheetWatcher() {
+  if (!user_style_sheet_watcher_.get()) {
+    user_style_sheet_watcher_ = new UserStyleSheetWatcher(GetPath());
+    user_style_sheet_watcher_->Init();
+  }
+  return user_style_sheet_watcher_.get();
+}
+
 HistoryService* ProfileImpl::GetHistoryService(ServiceAccessType sat) {
   if (!history_service_created_) {
     history_service_created_ = true;