Move the event attach/detach logic on unload from event.js to

chrome/browser/extensions/events_apitest.cc

Index: chrome/browser/extensions/events_apitest.cc
diff --git a/chrome/browser/extensions/events_apitest.cc b/chrome/browser/extensions/events_apitest.cc
index 3420022dc8b3ba664a153583b7ed8d65c89ae699..5fec2efa8891ade2a7bf242f0e90079f5dfd6f0e 100644
--- a/chrome/browser/extensions/events_apitest.cc
+++ b/chrome/browser/extensions/events_apitest.cc
@@ -4,6 +4,44 @@
 
 #include "chrome/browser/extensions/extension_apitest.h"
 
+#include "extensions/browser/event_router.h"
+#include "extensions/browser/extension_registry.h"
+
+using extensions::EventRouter;

[Devlin, 2015/04/10 18:10:39]

Can't we just shove this whole file into the extensions namespace?

[not at google - send to devlin, 2015/04/10 18:39:01]

Sure.

+using extensions::Extension;
+using extensions::ExtensionRegistry;
+
 IN_PROC_BROWSER_TEST_F(ExtensionApiTest, Events) {
   ASSERT_TRUE(RunExtensionTest("events")) << message_;
 }
+
+// Tests that events are unregistered when an extension page shuts down.
+IN_PROC_BROWSER_TEST_F(ExtensionApiTest, EventsAreUnregistered) {

[Devlin, 2015/04/10 18:10:39]

I trust this test fails without the rest of your patch?

[not at google - send to devlin, 2015/04/10 18:39:01]

The test passes without my patch, as it should - this is a refactor, after all.
It would be exceedingly hard to write a test which used to fail, but now passes
- one test would need to look for a memory leak (ugh), another test would need
to set up a corner case that I haven't managed to create myself (only
occasionally crashes IRL).

However, if I take out the logic which doesn't DetachEvent on
ScriptContext::Invalidate, the test does fail.

+  // In this test, page1.html registers for a number of events, then navigates
+  // to page2.html, which should unregister those events. page2.html notifies
+  // pass, by which point the event should have been unregistered.
+  EventRouter* event_router = EventRouter::Get(profile());
+  ExtensionRegistry* registry = ExtensionRegistry::Get(profile());
+
+  const char* test_extension_name = "events_are_unregistered";

[Devlin, 2015/04/10 18:10:39]

nit: may as well make this a std::string, since it'll be constructed into one
twice.

[not at google - send to devlin, 2015/04/10 18:39:01]

If you insist.

Plus I like the look of "const char*", vim makes it green.

+  ASSERT_TRUE(RunExtensionSubtest(test_extension_name, "page1.html"))
+      << message_;
+
+  // Find the extension we just installed by looking for the path.
+  const Extension* extension =
+      GetExtensionByPath(registry->enabled_extensions(),
+                         test_data_dir_.AppendASCII(test_extension_name));
+  ASSERT_TRUE(extension);
+  std::string id = extension->id();
+
+  // The page has closed, so no matter what all events are no longer listened
+  // to.
+  EXPECT_FALSE(
+      event_router->ExtensionHasEventListener(id, "browserAction.onClicked"));
+  EXPECT_FALSE(
+      event_router->ExtensionHasEventListener(id, "runtime.onStartup"));
+  EXPECT_FALSE(
+      event_router->ExtensionHasEventListener(id, "runtime.onSuspend"));
+  EXPECT_FALSE(
+      event_router->ExtensionHasEventListener(id, "runtime.onInstalled"));
+}