Tracks GVR version crossed with headset type using UMA.

chrome/browser/android/vr_shell/vr_metrics_util.cc

Index: chrome/browser/android/vr_shell/vr_metrics_util.cc
diff --git a/chrome/browser/android/vr_shell/vr_metrics_util.cc b/chrome/browser/android/vr_shell/vr_metrics_util.cc
new file mode 100644
index 0000000000000000000000000000000000000000..566745aab602dfea4f8eabf2aad2e626f70f6416
--- /dev/null
+++ b/chrome/browser/android/vr_shell/vr_metrics_util.cc
@@ -0,0 +1,86 @@
+// 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 kVrNotSupported = -3;
+static constexpr int kGvrNotInstalled = -2;
+static constexpr int kGvrTooOld = -1;
+
+namespace vr_shell {
+
+bool VrMetricsUtil::has_logged_gvr_version_ = false;
+
+void VrMetricsUtil::LogGvrVersionForVrViewerType(
+    gvr_context* context,
+    const VrCoreInfo& vr_core_info) {
+  if (has_logged_gvr_version_) {

[ddorwin, 2017/05/24 07:31:38]

nit: "gvr" is probably irrelevant here, and you wouldn't want that if you
extracted this into a cross-platform method. This might be runtime or
vr_runtime.

[tiborg, 2017/05/25 00:06:03]

Done.

+    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_gvr_version;

[ddorwin, 2017/05/24 07:31:37]

Initialize even though it should be set.

[tiborg, 2017/05/25 00:06:02]

Done.

+  switch (vr_core_info.compatibility) {
+    case VrCoreCompatibility::VR_CORE_COMPATIBILITY_VR_NOT_SUPPORTED:
+      encoded_gvr_version = kVrNotSupported;

[ddorwin, 2017/05/24 07:31:37]

nit: As above, "gvr" is irrelevant. Dropping is a simple choice here.

[tiborg, 2017/05/25 00:06:03]

Done.

+      break;
+    case VrCoreCompatibility::VR_CORE_COMPATIBILITY_VR_NOT_AVAILABLE:
+      encoded_gvr_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_gvr_version = kGvrTooOld;
+        break;
+      }

[ddorwin, 2017/05/24 07:31:38]

If you intend to fall through in the else case, please add an explicit comment.
Otherwise, this looks like a bug.

[tiborg, 2017/05/25 00:06:03]

Done.

+    case VrCoreCompatibility::VR_CORE_COMPATIBILITY_VR_READY:
+      encoded_gvr_version =
+          std::min(vr_core_info.gvr_version.major, 999) * 1000000 +

[ddorwin, 2017/05/24 07:31:38]

nit: 1000 * 1000 can be easier to read and make the reason clearer.

[tiborg, 2017/05/25 00:06:02]

Done.

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