Makes GetComponentExtensionResourceManager() thread-safe.

chrome/browser/extensions/chrome_extensions_browser_client.cc

Index: chrome/browser/extensions/chrome_extensions_browser_client.cc
diff --git a/chrome/browser/extensions/chrome_extensions_browser_client.cc b/chrome/browser/extensions/chrome_extensions_browser_client.cc
index 7ac696153bf760732582656ea5e87083737d5f08..d6a4a434408cdcbf3d01e0b0ce566422f1100a24 100644
--- a/chrome/browser/extensions/chrome_extensions_browser_client.cc
+++ b/chrome/browser/extensions/chrome_extensions_browser_client.cc
@@ -53,6 +53,7 @@ ChromeExtensionsBrowserClient::ChromeExtensionsBrowserClient() {
   // Only set if it hasn't already been set (e.g. by a test).
   if (GetCurrentChannel() == GetDefaultChannel())
     SetCurrentChannel(chrome::VersionInfo::GetChannel());
+  resource_manager_.reset(new ChromeComponentExtensionResourceManager());
 }
 
 ChromeExtensionsBrowserClient::~ChromeExtensionsBrowserClient() {}
@@ -251,10 +252,8 @@ ChromeExtensionsBrowserClient::CreateRuntimeAPIDelegate(
       new ChromeRuntimeAPIDelegate(context));
 }
 
-ComponentExtensionResourceManager*
+const ComponentExtensionResourceManager*
 ChromeExtensionsBrowserClient::GetComponentExtensionResourceManager() {
-  if (!resource_manager_)
-    resource_manager_.reset(new ChromeComponentExtensionResourceManager());
   return resource_manager_.get();
 }