Tracks GVR version crossed with headset type using UMA.

chrome/browser/android/vr_shell/vr_metrics_util.cc

+// Copyright 2017 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 "chrome/browser/android/vr_shell/vr_metrics_util.h"
+
+#include "base/metrics/histogram_macros.h"
+
+static constexpr int kVersionEncodingError = -4;
+static constexpr int kVrNotSupported = -3;
+static constexpr int kGvrNotInstalled = -2;
+static constexpr int kGvrTooOld = -1;
+
+namespace vr_shell {
+
+bool VrMetricsUtil::has_logged_vr_runtime_version_ = false;
+
+void VrMetricsUtil::LogGvrVersionForVrViewerType(
+    gvr_context* context,
+    const VrCoreInfo& vr_core_info) {
+  if (has_logged_vr_runtime_version_) {
+    return;
+  }
+
+  ViewerType vr_viewer_type =
+      context ? GetVrViewerType(context) : ViewerType::UNKNOWN_TYPE;
+  std::string histogram_name;
+  switch (vr_viewer_type) {
+    case ViewerType::CARDBOARD:
+      histogram_name = "VRRuntimeVersion.GVR.Cardboard";
+      break;
+    case ViewerType::DAYDREAM:
+      histogram_name = "VRRuntimeVersion.GVR.Daydream";
+      break;
+    default:
+      histogram_name = "VRRuntimeVersion.GVR.Unknown";
+      break;
+  }
+
+  uint32_t encoded_version = kVersionEncodingError;
+  switch (vr_core_info.compatibility) {
+    case VrCoreCompatibility::VR_CORE_COMPATIBILITY_VR_NOT_SUPPORTED:
+      encoded_version = kVrNotSupported;
+      break;
+    case VrCoreCompatibility::VR_CORE_COMPATIBILITY_VR_NOT_AVAILABLE:
+      encoded_version = kGvrNotInstalled;
+      break;
+    case VrCoreCompatibility::VR_CORE_COMPATIBILITY_VR_OUT_OF_DATE:
+      if (vr_core_info.gvr_version.major == 0 &&
+          vr_core_info.gvr_version.minor == 0 &&
+          vr_core_info.gvr_version.patch == 0) {
+        encoded_version = kGvrTooOld;
+        break;
+      }
+    // We fall through to

[ddorwin, 2017/05/25 16:42:26]

We generally avoid "we" in comments, especially in the first case. So just "Fall
through..." Also, I don't think you need to state the value we are falling
through to - this is obvious from the code, prone to rot, and makes the comment
longer and more difficult to read.

[tiborg, 2017/05/25 21:41:42]

Done.

+    // VrCoreCompatibility::VR_CORE_COMPATIBILITY_VR_READY since we can log

[ddorwin, 2017/05/25 16:42:26]

This should be indented with the above text. (I hope clang format doesn't break
that.)

[tiborg, 2017/05/25 21:41:42]

Clang-format moved it into the next line. However, per the other comment the
long value name is now gone anyway.

+    // a version in this case.
+    case VrCoreCompatibility::VR_CORE_COMPATIBILITY_VR_READY:
+      encoded_version =
+          std::min(vr_core_info.gvr_version.major, 999) * 1000 * 1000 +
+          std::min(vr_core_info.gvr_version.minor, 999) * 1000 +
+          std::min(vr_core_info.gvr_version.patch, 999);
+      break;
+  }
+
+  UMA_HISTOGRAM_SPARSE_SLOWLY(histogram_name.c_str(), encoded_version);

[rkaplow, 2017/05/25 20:57:27]

since this is using macros this should actually be
"VRRuntimeVersion.GVR.Cardboard" - i.e. move switch to here

[tiborg, 2017/05/25 21:41:42]

Done.

+
+  has_logged_vr_runtime_version_ = true;
+}
+
+void VrMetricsUtil::LogVrViewerType(gvr_context* context) {
+  UMA_HISTOGRAM_ENUMERATION("VRViewerType",

[rkaplow, 2017/05/25 20:57:27]

add xml for this?

[tiborg, 2017/05/25 21:41:42]

There already is an entry for this:
https://cs.chromium.org/chromium/src/tools/metrics/histograms/histograms.xml?...

+                            static_cast<int>(GetVrViewerType(context)),
+                            static_cast<int>(ViewerType::VIEWER_TYPE_MAX));
+}
+
+ViewerType VrMetricsUtil::GetVrViewerType(gvr_context* context) {
+  auto gvr_api = gvr::GvrApi::WrapNonOwned(context);
+  switch (gvr_api->GetViewerType()) {
+    case gvr::ViewerType::GVR_VIEWER_TYPE_DAYDREAM:
+      return ViewerType::DAYDREAM;
+    case gvr::ViewerType::GVR_VIEWER_TYPE_CARDBOARD:
+      return ViewerType::CARDBOARD;
+    default:
+      NOTREACHED();
+      return ViewerType::UNKNOWN_TYPE;
+  }
+}
+
+}  // namespace vr_shell