Cleanup template in 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 74ff8bca68b1e93fc063e9b4fe1c63c45095f703..e10776dfd86230c0c4dc7b5216dd93786b9d78b9 100644
--- a/media/base/cdm_promise.cc
+++ b/media/base/cdm_promise.cc
@@ -10,17 +10,46 @@
 
 namespace media {
 
-CdmPromise::CdmPromise() : is_pending_(true) {
-}
-
-CdmPromise::CdmPromise(PromiseRejectedCB reject_cb)
-    : reject_cb_(reject_cb), is_pending_(true) {
+template <typename T>
+struct CdmPromiseTraits {};
+
+template <>
+struct CdmPromiseTraits<void> {
+  static const CdmPromise::ResolveParameterType kType = CdmPromise::VOID_TYPE;
+};
+
+template <>
+struct CdmPromiseTraits<std::string> {
+  static const CdmPromise::ResolveParameterType kType = CdmPromise::STRING_TYPE;
+};
+
+template <>
+struct CdmPromiseTraits<KeyIdsVector> {
+  static const CdmPromise::ResolveParameterType kType =
+      CdmPromise::KEY_IDS_VECTOR_TYPE;
+};
+
+CdmPromise::CdmPromise(ResolveParameterType parameter_type)
+    : parameter_type_(parameter_type), is_pending_(true) {
+}
+
+CdmPromise::CdmPromise(ResolveParameterType parameter_type,
+                       PromiseRejectedCB reject_cb)
+    : parameter_type_(parameter_type),
+      reject_cb_(reject_cb),
+      is_pending_(true) {
   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) {
+CdmPromise::CdmPromise(ResolveParameterType parameter_type,
+                       PromiseRejectedCB reject_cb,
+                       const std::string& uma_name)
+    : parameter_type_(parameter_type),
+      reject_cb_(reject_cb),
+      is_pending_(true),
+      uma_name_(uma_name) {
   DCHECK(!reject_cb_.is_null());
+  DCHECK(!uma_name_.empty());
 }
 
 CdmPromise::~CdmPromise() {
@@ -52,125 +81,80 @@ static CdmPromise::ResultCodeForUMA ConvertExceptionToUMAResult(
 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 = ConvertExceptionToUMAResult(exception_code);
-    base::LinearHistogram::FactoryGet(
-        uma_name_, 1, NUM_RESULT_CODES, NUM_RESULT_CODES + 1,
-        base::HistogramBase::kUmaTargetedHistogramFlag)->Add(result_code);
-  }
+  ReportResultToUMA(ConvertExceptionToUMAResult(exception_code));
   reject_cb_.Run(exception_code, system_code, error_message);
 }
 
-CdmPromiseTemplate<void>::CdmPromiseTemplate(base::Callback<void()> resolve_cb,
-                                             PromiseRejectedCB reject_cb)
-    : CdmPromise(reject_cb), resolve_cb_(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());
-  DCHECK(!uma_name_.empty());
-}
-
-CdmPromiseTemplate<void>::CdmPromiseTemplate() {
-}
-
-CdmPromiseTemplate<void>::~CdmPromiseTemplate() {
-  DCHECK(!is_pending_);
-}
-
-void CdmPromiseTemplate<void>::resolve() {
+void CdmPromise::ReportResultToUMA(ResultCodeForUMA result) {
   DCHECK(is_pending_);
   is_pending_ = false;
   if (!uma_name_.empty()) {
     base::LinearHistogram::FactoryGet(
-        uma_name_, 1, NUM_RESULT_CODES, NUM_RESULT_CODES + 1,
-        base::HistogramBase::kUmaTargetedHistogramFlag)->Add(SUCCESS);
+        uma_name_,
+        1,
+        NUM_RESULT_CODES,
+        NUM_RESULT_CODES + 1,
+        base::HistogramBase::kUmaTargetedHistogramFlag)->Add(result);
   }
-  resolve_cb_.Run();
-}
-
-CdmPromise::ResolveParameterType
-CdmPromiseTemplate<void>::GetResolveParameterType() const {
-  return VOID_TYPE;
 }
 
-CdmPromiseTemplate<std::string>::CdmPromiseTemplate(
-    base::Callback<void(const std::string&)> resolve_cb,
+template <typename T>
+CdmPromiseTemplate<T>::CdmPromiseTemplate(
+    base::Callback<void(const T&)> resolve_cb,
     PromiseRejectedCB reject_cb)
-    : CdmPromise(reject_cb), resolve_cb_(resolve_cb) {
+    : CdmPromise(CdmPromiseTraits<T>::kType, reject_cb),
+      resolve_cb_(resolve_cb) {
   DCHECK(!resolve_cb_.is_null());
 }
 
-CdmPromiseTemplate<std::string>::CdmPromiseTemplate(
-    base::Callback<void(const std::string&)> resolve_cb,
+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) {
+    : CdmPromise(CdmPromiseTraits<T>::kType, reject_cb, uma_name),
+      resolve_cb_(resolve_cb) {
   DCHECK(!resolve_cb_.is_null());
 }
 
-CdmPromiseTemplate<std::string>::CdmPromiseTemplate() {
+template <typename T>
+CdmPromiseTemplate<T>::CdmPromiseTemplate()
+    : CdmPromise(CdmPromiseTraits<T>::kType) {
 }
 
-CdmPromiseTemplate<std::string>::~CdmPromiseTemplate() {
-  DCHECK(!is_pending_);
-}
-
-void CdmPromiseTemplate<std::string>::resolve(const std::string& result) {
-  DCHECK(is_pending_);
-  is_pending_ = false;
-  if (!uma_name_.empty()) {
-    base::LinearHistogram::FactoryGet(
-        uma_name_, 1, NUM_RESULT_CODES, NUM_RESULT_CODES + 1,
-        base::HistogramBase::kUmaTargetedHistogramFlag)->Add(SUCCESS);
-  }
+template <typename T>
+void CdmPromiseTemplate<T>::resolve(const T& result) {
+  ReportResultToUMA(SUCCESS);
   resolve_cb_.Run(result);
 }
 
-CdmPromise::ResolveParameterType
-CdmPromiseTemplate<std::string>::GetResolveParameterType() const {
-  return STRING_TYPE;
-}
-
-CdmPromiseTemplate<KeyIdsVector>::CdmPromiseTemplate(
-    base::Callback<void(const KeyIdsVector&)> resolve_cb,
-    PromiseRejectedCB reject_cb)
-    : CdmPromise(reject_cb), resolve_cb_(resolve_cb) {
+CdmPromiseTemplate<void>::CdmPromiseTemplate(base::Callback<void()> resolve_cb,
+                                             PromiseRejectedCB reject_cb)
+    : CdmPromise(CdmPromiseTraits<void>::kType, reject_cb),
+      resolve_cb_(resolve_cb) {
   DCHECK(!resolve_cb_.is_null());
 }
 
-CdmPromiseTemplate<KeyIdsVector>::CdmPromiseTemplate(
-    base::Callback<void(const KeyIdsVector&)> resolve_cb,
-    PromiseRejectedCB reject_cb,
-    const std::string& uma_name)
-    : CdmPromise(reject_cb, uma_name), resolve_cb_(resolve_cb) {
+CdmPromiseTemplate<void>::CdmPromiseTemplate(base::Callback<void()> resolve_cb,
+                                             PromiseRejectedCB reject_cb,
+                                             const std::string& uma_name)
+    : CdmPromise(CdmPromiseTraits<void>::kType, reject_cb, uma_name),
+      resolve_cb_(resolve_cb) {
   DCHECK(!resolve_cb_.is_null());
+  DCHECK(!uma_name_.empty());
 }
 
-CdmPromiseTemplate<KeyIdsVector>::~CdmPromiseTemplate() {
-  DCHECK(!is_pending_);
+CdmPromiseTemplate<void>::CdmPromiseTemplate()
+    : CdmPromise(CdmPromiseTraits<void>::kType) {
 }
 
-void CdmPromiseTemplate<KeyIdsVector>::resolve(const KeyIdsVector& result) {
-  DCHECK(is_pending_);
-  is_pending_ = false;
-  if (!uma_name_.empty()) {
-    base::LinearHistogram::FactoryGet(
-        uma_name_, 1, NUM_RESULT_CODES, NUM_RESULT_CODES + 1,
-        base::HistogramBase::kUmaTargetedHistogramFlag)->Add(SUCCESS);
-  }
-  resolve_cb_.Run(result);
+void CdmPromiseTemplate<void>::resolve() {
+  ReportResultToUMA(SUCCESS);
+  resolve_cb_.Run();
 }
 
-CdmPromise::ResolveParameterType
-CdmPromiseTemplate<KeyIdsVector>::GetResolveParameterType() const {
-  return KEY_IDS_VECTOR_TYPE;
-}
+// Explicit template instantiation for the Promises needed.
+template class MEDIA_EXPORT CdmPromiseTemplate<std::string>;
+template class MEDIA_EXPORT CdmPromiseTemplate<KeyIdsVector>;
 
 }  // namespace media