Remove unneeded extension_messages_browsertest.cc + cleanup.

chrome/renderer/extensions/chrome_v8_context_set_unittest.cc

Index: chrome/renderer/extensions/chrome_v8_context_set_unittest.cc
diff --git a/chrome/renderer/extensions/chrome_v8_context_set_unittest.cc b/chrome/renderer/extensions/chrome_v8_context_set_unittest.cc
index 818e2cd13f7fc1993dad313bc5778b5732c75d97..92443aa4af5ec8f7bc9c96fc5656addd93905c17 100644
--- a/chrome/renderer/extensions/chrome_v8_context_set_unittest.cc
+++ b/chrome/renderer/extensions/chrome_v8_context_set_unittest.cc
@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 #include "base/message_loop.h"
+#include "chrome/common/extensions/extension.h"
 #include "chrome/common/extensions/feature.h"
 #include "chrome/renderer/extensions/chrome_v8_context.h"
 #include "chrome/renderer/extensions/chrome_v8_context_set.h"
@@ -21,11 +22,11 @@ TEST(ChromeV8ContextSet, Lifecycle) {
   // Dirty hack, but we don't actually need the frame, and this is easier than
   // creating a whole webview.
   WebKit::WebFrame* frame = reinterpret_cast<WebKit::WebFrame*>(1);
-  std::string extension_id = "00000000000000000000000000000000";
+  const Extension* extension = NULL;
   ChromeV8Context* context = new ChromeV8Context(
       v8_context,
       frame,
-      extension_id,
+      extension,
       extensions::Feature::BLESSED_EXTENSION_CONTEXT);
 
   context_set.Add(context);