Improve unit testing of socket API.

chrome/browser/extensions/api/socket/socket_api.cc

Index: chrome/browser/extensions/api/socket/socket_api.cc
diff --git a/chrome/browser/extensions/api/socket/socket_api.cc b/chrome/browser/extensions/api/socket/socket_api.cc
index 9848020c1725a3d8682f1b6c0f284d0aaecbbe5c..637d6147dd7d62a2c41f92f719cd693a54b5a66e 100644
--- a/chrome/browser/extensions/api/socket/socket_api.cc
+++ b/chrome/browser/extensions/api/socket/socket_api.cc
@@ -42,6 +42,8 @@ SocketAsyncApiFunction::~SocketAsyncApiFunction() {
 
 bool SocketAsyncApiFunction::PrePrepare() {
   manager_ = ExtensionSystem::Get(profile())->socket_manager();
+  DCHECK(manager_) << "There is no socket manager. " <<
+      "It is likely you are testing this API in an isolated environment.";

[asargent_no_longer_on_chrome, 2012/07/23 16:57:57]

nit: I think this second line of error output is probably unnecessary. If you
want to keep it, a suggested change would be to something like "If you are using
this object in a test, you need to provide a socket manager implementation"

   return manager_ != NULL;
 }