media: Unify NotSupported message in key system config selection

This CL drops the error message parameter in the |not_supported_cb|
passed to KeySystemConfigSelector::SelectConfig() so that the error
message for not supported key system or config is always the same, as
specified in WebEncryptedMediaClientImpl::OnRequestNotSupported().

BUG=760720

Change-Id: I3dd6de9a112efe4dd753be1e38b510740523dc6a
Reviewed-on: https://chromium-review.googlesource.com/772968
Commit-Queue: Xiaohan Wang <xhwang@chromium.org>
Reviewed-by: David Dorwin <ddorwin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#516994}

media/blink/key_system_config_selector.cc

@@ -33,13 +33,6 @@ using EmeFeatureRequirement =
 
 namespace {
 
-// The rejection message when the key system is not supported or when none of
-// the requested configurations is supported should always be the same to help
-// avoid leaking internal information unnecessarily.
-// See https://crbug.com/760720
-const char kUnsupportedKeySystemOrConfigMessage[] =
-    "Unsupported keySystem or supportedConfigurations.";
-
 static EmeConfigRule GetSessionTypeConfigRule(EmeSessionTypeSupport support) {
   switch (support) {
     case EmeSessionTypeSupport::INVALID:
@@ -165,7 +158,7 @@ struct KeySystemConfigSelector::SelectionRequest {
   blink::WebSecurityOrigin security_origin;
   base::Callback<void(const blink::WebMediaKeySystemConfiguration&,
                       const CdmConfig&)> succeeded_cb;
-  base::Callback<void(const blink::WebString&)> not_supported_cb;
+  base::Closure not_supported_cb;
   bool was_permission_requested = false;
   bool is_permission_granted = false;
 };
@@ -860,7 +853,7 @@ void KeySystemConfigSelector::SelectConfig(
     const blink::WebSecurityOrigin& security_origin,
     base::Callback<void(const blink::WebMediaKeySystemConfiguration&,
                         const CdmConfig&)> succeeded_cb,
-    base::Callback<void(const blink::WebString&)> not_supported_cb) {
+    base::Closure not_supported_cb) {
   // Continued from requestMediaKeySystemAccess(), step 6, from
   // https://w3c.github.io/encrypted-media/#requestmediakeysystemaccess
   //
@@ -868,13 +861,13 @@ void KeySystemConfigSelector::SelectConfig(
   //     agent, reject promise with a NotSupportedError. String comparison
   //     is case-sensitive.
   if (!key_system.ContainsOnlyASCII()) {
-    not_supported_cb.Run(kUnsupportedKeySystemOrConfigMessage);
+    not_supported_cb.Run();
     return;
   }
 
   std::string key_system_ascii = key_system.Ascii();
   if (!key_systems_->IsSupportedKeySystem(key_system_ascii)) {
-    not_supported_cb.Run(kUnsupportedKeySystemOrConfigMessage);
+    not_supported_cb.Run();
     return;
   }
 
@@ -896,7 +889,7 @@ void KeySystemConfigSelector::SelectConfig(
   // Therefore, always support Clear Key key system and only check settings for
   // other key systems.
   if (!is_encrypted_media_enabled && !IsClearKey(key_system_ascii)) {
-    not_supported_cb.Run(kUnsupportedKeySystemOrConfigMessage);
+    not_supported_cb.Run();
     return;
   }
 
@@ -970,7 +963,7 @@ void KeySystemConfigSelector::SelectConfigInternal(
   }
 
   // 6.4. Reject promise with a NotSupportedError.
-  request->not_supported_cb.Run(kUnsupportedKeySystemOrConfigMessage);
+  request->not_supported_cb.Run();
 }
 
 void KeySystemConfigSelector::OnPermissionResult(

media/blink/key_system_config_selector.h

@@ -46,7 +46,7 @@ class MEDIA_BLINK_EXPORT KeySystemConfigSelector {
       const blink::WebSecurityOrigin& security_origin,
       base::Callback<void(const blink::WebMediaKeySystemConfiguration&,
                           const CdmConfig&)> succeeded_cb,
-      base::Callback<void(const blink::WebString&)> not_supported_cb);
+      base::Closure not_supported_cb);
 
  private:
   struct SelectionRequest;

media/blink/key_system_config_selector_unittest.cc

@@ -276,7 +276,7 @@ class KeySystemConfigSelectorTest : public testing::Test {
     config_ = result;
   }
 
-  void OnNotSupported(const blink::WebString&) { not_supported_count_++; }
+  void OnNotSupported() { not_supported_count_++; }
 
   std::unique_ptr<FakeKeySystems> key_systems_;
   std::unique_ptr<FakeMediaPermission> media_permission_;

media/blink/webencryptedmediaclient_impl.cc

@@ -152,9 +152,14 @@ void WebEncryptedMediaClientImpl::OnRequestSucceeded(
 }
 
 void WebEncryptedMediaClientImpl::OnRequestNotSupported(
-    blink::WebEncryptedMediaRequest request,
-    const blink::WebString& error_message) {
-  request.RequestNotSupported(error_message);
+    blink::WebEncryptedMediaRequest request) {
+  // The rejection message when the key system is not supported or when none of
+  // the requested configurations is supported should always be the same to help
+  // avoid leaking information unnecessarily. See https://crbug.com/760720
+  const char kUnsupportedKeySystemOrConfigMessage[] =
+      "Unsupported keySystem or supportedConfigurations.";
+
+  request.RequestNotSupported(kUnsupportedKeySystemOrConfigMessage);
 }
 
 WebEncryptedMediaClientImpl::Reporter* WebEncryptedMediaClientImpl::GetReporter(

media/blink/webencryptedmediaclient_impl.h

@@ -65,9 +65,8 @@ class MEDIA_BLINK_EXPORT WebEncryptedMediaClientImpl
       const blink::WebMediaKeySystemConfiguration& accumulated_configuration,
       const CdmConfig& cdm_config);
 
-  // Complete a requestMediaKeySystemAccess() request with an error message.
-  void OnRequestNotSupported(blink::WebEncryptedMediaRequest request,
-                             const blink::WebString& error_message);
+  // Complete a requestMediaKeySystemAccess() request with a NotSupportedError.
+  void OnRequestNotSupported(blink::WebEncryptedMediaRequest request);
 
   // Gets the Reporter for |key_system|. If it doesn't already exist,
   // create one.