Add UMA reporting to CdmPromise.

media/base/cdm_promise.cc

Index: media/base/cdm_promise.cc
diff --git a/media/base/cdm_promise.cc b/media/base/cdm_promise.cc
index ec5e913dbb8aae93c90aa30a24835aaa1a3cc3e8..ce5974f5e4cd8a711a5a161c51b82eb8bc8ef9cb 100644
--- a/media/base/cdm_promise.cc
+++ b/media/base/cdm_promise.cc
@@ -6,6 +6,7 @@
 
 #include "base/bind.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 
 namespace media {
 
@@ -17,15 +18,47 @@ CdmPromise::CdmPromise(PromiseRejectedCB reject_cb)
   DCHECK(!reject_cb_.is_null());
 }
 
+CdmPromise::CdmPromise(PromiseRejectedCB reject_cb, const std::string& uma_name)
+    : reject_cb_(reject_cb), is_pending_(true), uma_name_(uma_name) {
+  DCHECK(!reject_cb_.is_null());
+}
+
 CdmPromise::~CdmPromise() {
   DCHECK(!is_pending_);
 }
 
+static CdmPromise::ResultCodeForUMA ConvertException(

[ddorwin, 2014/08/08 03:35:40]

..ToUMAResult

[sandersd (OOO until July 31), 2014/08/08 17:22:24]

Done.

+    MediaKeys::Exception exception_code) {
+  switch (exception_code) {
+    case MediaKeys::NOT_SUPPORTED_ERROR:
+      return CdmPromise::NOT_SUPPORTED_ERROR;
+    case MediaKeys::INVALID_STATE_ERROR:
+      return CdmPromise::INVALID_STATE_ERROR;
+    case MediaKeys::INVALID_ACCESS_ERROR:
+      return CdmPromise::INVALID_ACCESS_ERROR;
+    case MediaKeys::QUOTA_EXCEEDED_ERROR:
+      return CdmPromise::QUOTA_EXCEEDED_ERROR;
+    case MediaKeys::UNKNOWN_ERROR:
+      return CdmPromise::UNKNOWN_ERROR;
+    case MediaKeys::CLIENT_ERROR:
+      return CdmPromise::CLIENT_ERROR;
+    case MediaKeys::OUTPUT_ERROR:
+      return CdmPromise::OUTPUT_ERROR;
+    default:
+      NOTREACHED();
+      return CdmPromise::UNKNOWN_ERROR;

[ddorwin, 2014/08/08 03:35:40]

Maybe we should have a UMA value (1) for unexpected. (UNKNOWN is an actual DOM
exception.)

[sandersd (OOO until July 31), 2014/08/08 17:22:24]

I'm a little reluctant to add a debugging feature here, perhaps it would be
better to add a unittest that checks for a difference?

+  }
+}
+
 void CdmPromise::reject(MediaKeys::Exception exception_code,
                         uint32 system_code,
                         const std::string& error_message) {
   DCHECK(is_pending_);
   is_pending_ = false;
+  if (!uma_name_.empty()) {
+    ResultCodeForUMA result_code = ConvertException(exception_code);
+    UMA_HISTOGRAM_ENUMERATION(uma_name_, result_code, NUM_RESULT_CODES);
+  }
   reject_cb_.Run(exception_code, system_code, error_message);
 }
 
@@ -38,6 +71,15 @@ CdmPromiseTemplate<T>::CdmPromiseTemplate(
 }
 
 template <typename T>
+CdmPromiseTemplate<T>::CdmPromiseTemplate(
+    base::Callback<void(const T&)> resolve_cb,
+    PromiseRejectedCB reject_cb,
+    const std::string& uma_name)
+    : CdmPromise(reject_cb, uma_name), resolve_cb_(resolve_cb) {
+  DCHECK(!resolve_cb_.is_null());
+}
+
+template <typename T>
 CdmPromiseTemplate<T>::~CdmPromiseTemplate() {
   DCHECK(!is_pending_);
 }
@@ -46,6 +88,8 @@ template <typename T>
 void CdmPromiseTemplate<T>::resolve(const T& result) {
   DCHECK(is_pending_);
   is_pending_ = false;
+  if (!uma_name_.empty())
+    UMA_HISTOGRAM_ENUMERATION(uma_name_, SUCCESS, NUM_RESULT_CODES);
   resolve_cb_.Run(result);
 }
 
@@ -55,6 +99,13 @@ CdmPromiseTemplate<void>::CdmPromiseTemplate(base::Callback<void()> resolve_cb,
   DCHECK(!resolve_cb_.is_null());
 }
 
+CdmPromiseTemplate<void>::CdmPromiseTemplate(base::Callback<void()> resolve_cb,
+                                             PromiseRejectedCB reject_cb,
+                                             const std::string& uma_name)
+    : CdmPromise(reject_cb, uma_name), resolve_cb_(resolve_cb) {
+  DCHECK(!resolve_cb_.is_null());
+}
+
 CdmPromiseTemplate<void>::CdmPromiseTemplate() {
 }
 
@@ -65,6 +116,8 @@ CdmPromiseTemplate<void>::~CdmPromiseTemplate() {
 void CdmPromiseTemplate<void>::resolve() {
   DCHECK(is_pending_);
   is_pending_ = false;
+  if (!uma_name_.empty())
+    UMA_HISTOGRAM_ENUMERATION(uma_name_, SUCCESS, NUM_RESULT_CODES);
   resolve_cb_.Run();
 }