Deflake ComponentExtensionRuntimeReload test and re-enable.

chrome/browser/apps/app_browsertest.cc

Index: chrome/browser/apps/app_browsertest.cc
diff --git a/chrome/browser/apps/app_browsertest.cc b/chrome/browser/apps/app_browsertest.cc
index 1c837c2d83972a9b0ceaa983665fba993d368225..ac777e66746cccd3d84025a02032d29837627d7f 100644
--- a/chrome/browser/apps/app_browsertest.cc
+++ b/chrome/browser/apps/app_browsertest.cc
@@ -1054,7 +1054,7 @@ IN_PROC_BROWSER_TEST_F(PlatformAppBrowserTest, ComponentAppBackgroundPage) {
 
 // Flaky: http://crbug.com/407409

[tapted, 2014/09/23 00:16:33]

This can be removed, or replaced with a brief description of the test.

[Anand Mistry (off Chromium), 2014/09/23 00:25:43]

Removed. No longer relevant.

 IN_PROC_BROWSER_TEST_F(PlatformAppBrowserTest,
-                       DISABLED_ComponentExtensionRuntimeReload) {
+                       ComponentExtensionRuntimeReload) {
   // Ensure that we wait until the background page is run (to register the
   // OnLaunched listener) before trying to open the application. This is similar
   // to LoadAndLaunchPlatformApp, but we want to load as a component extension.
@@ -1077,7 +1077,13 @@ IN_PROC_BROWSER_TEST_F(PlatformAppBrowserTest,
 
   {
     ASSERT_TRUE(ExecuteScriptInBackgroundPageNoWait(
-        extension->id(), "chrome.runtime.reload();"));
+        extension->id(),
+        // NoWait actually waits for a domAutomationController.send() which is
+        // implicitly append to the script. Since reload() restarts the
+        // extension, the send after reload may not get executed. To get around
+        // this, send first, then execute the reload().
+        "window.domAutomationController.send(0);"
+        "chrome.runtime.reload();"));
     ExtensionTestMessageListener launched_listener("Launched", false);

[tapted, 2014/09/23 00:16:33]

should this come before the ExecuteScript? Otherwise I think it can miss seeing
the message. (e.g. what happens if you put a sleep(10) before this line?)

[Anand Mistry (off Chromium), 2014/09/23 00:25:43]

Done.

[tapted, 2014/09/23 00:48:00]

(actually I realised after I sent this that a sleep(..) here probably won't make
a flake - the message will still be queued - but since
ExecuteScriptInBackgroundPageNoWait(.) is spinning its own runloops, it's better
to have the listener listening throughout.) /allgood

     ASSERT_TRUE(launched_listener.WaitUntilSatisfied());
   }