Rename UpdateCheckAction|Params to OmahaRequestAction|Params.

Also, renamed UpdateCheckResponse to OmahaResponse.

BUG=560
TEST=unit tests, gmerge'd on device.

Review URL: http://codereview.chromium.org/2981007
diff --git a/omaha_response_handler_action.cc b/omaha_response_handler_action.cc
index 486f19b..319c825 100644
--- a/omaha_response_handler_action.cc
+++ b/omaha_response_handler_action.cc
@@ -20,7 +20,7 @@
 void OmahaResponseHandlerAction::PerformAction() {
   CHECK(HasInputObject());
   ScopedActionCompleter completer(processor_, this);
-  const UpdateCheckResponse& response = GetInputObject();
+  const OmahaResponse& response = GetInputObject();
   if (!response.update_exists) {
     got_no_update_response_ = true;
     LOG(INFO) << "There are no updates. Aborting.";
@@ -42,7 +42,7 @@
     SetOutputObject(install_plan_);
   LOG(INFO) << "Using this install plan:";
   install_plan_.Dump();
-  
+
   completer.set_success(true);
 }