Add UMA reporting to CdmPromise.

media/base/cdm_promise.h

 // Copyright 2014 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 MEDIA_BASE_CDM_PROMISE_H_
 #define MEDIA_BASE_CDM_PROMISE_H_
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "media/base/media_export.h"
 #include "media/base/media_keys.h"
 
 namespace media {
 
 // Interface for promises being resolved/rejected in response to various
 // session actions. These may be called synchronously or asynchronously.
 // The promise must be resolved or rejected exactly once. It is expected that
 // the caller free the promise once it is resolved/rejected.
 //
 // This is only the base class, as parameter to resolve() varies.
 class MEDIA_EXPORT CdmPromise {
  public:
+  // A superset of media::MediaKeys::Exception for UMA reporting.
+  enum ResultCodeForUMA {
+    SUCCESS,
+    NOT_SUPPORTED_ERROR,
+    INVALID_STATE_ERROR,
+    INVALID_ACCESS_ERROR,
+    QUOTA_EXCEEDED_ERROR,
+    UNKNOWN_ERROR,
+    CLIENT_ERROR,
+    OUTPUT_ERROR,
+    NUM_RESULT_CODES
+  };
+
   typedef base::Callback<void(MediaKeys::Exception exception_code,
                               uint32 system_code,
                               const std::string& error_message)>
       PromiseRejectedCB;
 
   virtual ~CdmPromise();
 
   // Used to indicate that the operation failed. |exception_code| must be
   // specified. |system_code| is a Key System-specific value for the error
   // that occurred, or 0 if there is no associated status code or such status
   // codes are not supported by the Key System. |error_message| is optional.
   virtual void reject(MediaKeys::Exception exception_code,
                       uint32 system_code,
                       const std::string& error_message);
 
  protected:
   CdmPromise();
   CdmPromise(PromiseRejectedCB reject_cb);
 
+  // If constructed with a |uma_name| (which must be the name of a
+  // CdmPromiseResult UMA), CdmPromise will report the promise result (success
+  // or rejection code).
+  CdmPromise(PromiseRejectedCB reject_cb, const std::string& uma_name);
+
   PromiseRejectedCB reject_cb_;
 
   // Keep track of whether the promise hasn't been resolved or rejected yet.
   bool is_pending_;
 
+  // UMA to report result to.
+  std::string uma_name_;
+
   DISALLOW_COPY_AND_ASSIGN(CdmPromise);
 };
 
 template <typename T>
 class MEDIA_EXPORT CdmPromiseTemplate : public CdmPromise {
  public:
   CdmPromiseTemplate(base::Callback<void(const T&)> resolve_cb,
                      PromiseRejectedCB rejected_cb);
+  CdmPromiseTemplate(base::Callback<void(const T&)> resolve_cb,
+                     PromiseRejectedCB rejected_cb,
+                     const std::string& uma_name);
   virtual ~CdmPromiseTemplate();
   virtual void resolve(const T& result);
 
  private:
   base::Callback<void(const T&)> resolve_cb_;
 
   DISALLOW_COPY_AND_ASSIGN(CdmPromiseTemplate);
 };
 
 // Specialization for no parameter to resolve().
 template <>
 class MEDIA_EXPORT CdmPromiseTemplate<void> : public CdmPromise {
  public:
   CdmPromiseTemplate(base::Callback<void(void)> resolve_cb,
                      PromiseRejectedCB rejected_cb);
+  CdmPromiseTemplate(base::Callback<void(void)> resolve_cb,
+                     PromiseRejectedCB rejected_cb,
+                     const std::string& uma_name);
   virtual ~CdmPromiseTemplate();
   virtual void resolve();
 
  protected:
   // Allow subclasses to completely override the implementation.
   CdmPromiseTemplate();
 
  private:
   base::Callback<void(void)> resolve_cb_;
 
   DISALLOW_COPY_AND_ASSIGN(CdmPromiseTemplate);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_CDM_PROMISE_H_