Let MetricsService know about some Android Activities

chrome/browser/android/activity_type_ids.h

Index: chrome/browser/android/activity_type_ids.h
diff --git a/chrome/browser/android/activity_type_ids.h b/chrome/browser/android/activity_type_ids.h
new file mode 100644
index 0000000000000000000000000000000000000000..068b92be8a0c93c258d41990b0dc6cf4174dcb38
--- /dev/null
+++ b/chrome/browser/android/activity_type_ids.h
@@ -0,0 +1,43 @@
+// Copyright 2013 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.
+
+#ifndef CHROME_BROWSER_ANDROID_ACTIVITY_TYPE_IDS_H_
+#define CHROME_BROWSER_ANDROID_ACTIVITY_TYPE_IDS_H_
+
+// This file maps Activities on Chrome to specific flags for identification.
+#ifndef DEFINE_ACTIVITY_ID

[Alexei Svitkine (slow), 2014/01/09 20:20:12]

This is a bit messy.

I suggest splitting into two files, one that just has the macros and names (e.g.
like net_error_list.h[1]) and another that includes it that's meant to be used
directly by C++ code (e.g. with a header guard, the enum declaration, etc).

[1]
https://code.google.com/p/chromium/codesearch#chromium/src/net/base/net_error...

Then, you won't need these extra ifdefs. 

[Kibeom Kim (inactive), 2014/01/16 00:18:16]

Done.

+#define DEFINE_ACTIVITY_ID(id,value) ACTIVITY_##id = (value),
+#define CREATING_CPP_HEADER
+namespace ActivityTypeIds {
+enum Type {
+#endif  // DEFINE_ACTIVITY_ID
+
+
+
+// Define Activities we are interested in tracking.  IDs are assigned
+// consecutively, from NONE to MAX_VALUE.  Activities that are not explicitly
+// defined are all assigned the UNKNOWN value.  When adding new ones, make sure
+// to append them after current Activities and to update the |AndroidActivityId|
+// enum in |histograms.xml|.
+DEFINE_ACTIVITY_ID(NONE, 0)
+DEFINE_ACTIVITY_ID(UNKNOWN, 1)
+DEFINE_ACTIVITY_ID(MAIN, 2)
+DEFINE_ACTIVITY_ID(PREFERENCES, 3)
+DEFINE_ACTIVITY_ID(WEBAPPACTIVITY, 4)
+DEFINE_ACTIVITY_ID(FULLSCREENACTIVITY, 5)
+DEFINE_ACTIVITY_ID(MAX_VALUE, 6)
+
+
+
+#ifdef CREATING_CPP_HEADER
+};  // enum Type
+
+// Takes an int corresponding to a Type and returns the corresponding Type.
+Type GetActivityType(int type_id);
+}  // namespace ActivityTypeIds
+#undef CREATING_CPP_HEADER
+#undef DEFINE_ACTIVITY_ID
+#endif  // CREATING_CPP_HEADER
+
+#endif  // CHROME_BROWSER_ANDROID_ACTIVITY_TYPE_IDS_H_