Suppress the exception thrown when responding to message with no response callback.

chrome/browser/extensions/hotword_browsertest.cc

Index: chrome/browser/extensions/hotword_browsertest.cc
diff --git a/chrome/browser/extensions/hotword_browsertest.cc b/chrome/browser/extensions/hotword_browsertest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..f176d19e8b5765d3f143e1b39402dbb9dce4f029
--- /dev/null
+++ b/chrome/browser/extensions/hotword_browsertest.cc
@@ -0,0 +1,92 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/files/file_path.h"
+#include "base/path_service.h"
+#include "base/prefs/pref_service.h"
+#include "chrome/browser/extensions/component_loader.h"
+#include "chrome/browser/extensions/error_console/error_console.h"
+#include "chrome/browser/extensions/extension_browsertest.h"
+#include "chrome/browser/extensions/extension_service.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/common/pref_names.h"
+#include "chrome/test/base/ui_test_utils.h"
+#include "extensions/common/extension.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+
+namespace extensions {
+
+class HotwordBrowserTest : public ExtensionBrowserTest {
+ public:
+  HotwordBrowserTest() : error_console_(NULL) { }
+  virtual ~HotwordBrowserTest() { }
+
+ protected:
+  virtual void SetUpInProcessBrowserTestFixture() OVERRIDE {
+    ExtensionBrowserTest::SetUpInProcessBrowserTestFixture();
+
+    // We need a special flag to enable the hotword_helper extension.
+    base::CommandLine::ForCurrentProcess()->AppendSwitchASCII(
+        "force-fieldtrials", "VoiceTrigger/Install/");

[asargent_no_longer_on_chrome, 2014/09/24 19:19:59]

nit: Are there constants either of these strings that you can use instead of
duplicating the literals?

[Anand Mistry (off Chromium), 2014/09/25 00:53:23]

Yes for the first, no for the second.

+    // Load the hotword_helper extension.
+    ComponentLoader::EnableBackgroundExtensionsForTesting();
+
+    // We need to enable the ErrorConsole FeatureSwitch in order to collect
+    // errors. This should be enabled on any channel <= Dev, but let's make
+    // sure (in case a test is running on, e.g., a beta channel).
+    FeatureSwitch::error_console()->SetOverrideValue(
+        FeatureSwitch::OVERRIDE_ENABLED);
+  }
+
+  virtual void SetUpOnMainThread() OVERRIDE {
+    ExtensionBrowserTest::SetUpOnMainThread();
+
+    // Errors are only kept if we have Developer Mode enabled.
+    profile()->GetPrefs()->SetBoolean(prefs::kExtensionsUIDeveloperMode, true);
+
+    error_console_ = ErrorConsole::Get(profile());
+    ASSERT_TRUE(error_console_);
+  }
+
+  void RunMessageLoopForMs(int ms) {
+    base::MessageLoop::current()->PostDelayedTask(
+        FROM_HERE, base::MessageLoop::QuitWhenIdleClosure(),
+        base::TimeDelta::FromMilliseconds(ms));
+    content::RunMessageLoop();
+  }
+
+  ErrorConsole* error_console() { return error_console_; }
+
+ private:
+  // Weak reference to the ErrorConsole.
+  ErrorConsole* error_console_;
+
+  DISALLOW_COPY_AND_ASSIGN(HotwordBrowserTest);
+};
+
+// Test we silently capture an exception from a message handler's response
+// callback. This happens when the caller to chrome.runtime.sendMessage()
+// doesn't specify a response callback.
+IN_PROC_BROWSER_TEST_F(HotwordBrowserTest, MessageSendResponseError) {
+  // Enable error reporting for the hotword helper extension.
+  error_console()->SetReportingAllForExtension(
+      "dnhpdliibojhegemfjheidglijccjfmc",
+      true);
+
+  const Extension* extension = extension_service()->GetExtensionById(
+      "dnhpdliibojhegemfjheidglijccjfmc", false);

[asargent_no_longer_on_chrome, 2014/09/24 19:19:59]

nit: use a constant to avoid the id string duplication here

[Anand Mistry (off Chromium), 2014/09/25 00:53:23]

Done.

+  ASSERT_TRUE(extension);
+  const Extension* test_extension = LoadExtension(
+      test_data_dir_.AppendASCII("hotword"));
+  ASSERT_TRUE(test_extension);
+
+  // We're testing that an error doesn't happen. Since there's no event we can
+  // wait for, just sleep for a bit and check.
+  RunMessageLoopForMs(200);

[asargent_no_longer_on_chrome, 2014/09/24 19:19:59]

In the past doing this sort of "sleep for a fixed amount of time" approach has
not worked out well. One problem is that the production buildbots run in virtual
machines on nearly oversubscribed hardware, and things that take only a few
hundred MS on our fast z620's take substantially longer. 

A much better approach is to add some sort of event that gets fired from within
the extension once you're past the place where the error could happen, and
listen for it here. I know that's more work but I think it is probably worth it
to end up with a less flaky test. 

[Anand Mistry (off Chromium), 2014/09/25 00:53:23]

Done.

+
+  ASSERT_TRUE(error_console()->GetErrorsForExtension(extension->id()).empty());
+}
+
+}  // namespace extensions