Update supported key system info from browser process if needed.

content/renderer/media/crypto/key_systems.cc

 // Copyright 2013 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 "content/renderer/media/crypto/key_systems.h"
 
 #include <string>
 
 #include "base/containers/hash_tables.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/strings/string_util.h"
+#include "base/time/time.h"
 #include "content/public/common/content_client.h"
 #include "content/public/common/eme_codec.h"
 #include "content/public/renderer/content_renderer_client.h"
 #include "content/public/renderer/key_system_info.h"
 #include "content/renderer/media/crypto/key_systems_support_uma.h"
 
 #if defined(OS_ANDROID)
 #include "media/base/android/media_codec_bridge.h"
 #endif
 
@@ skipping 57 matching lines @@
 
   info.use_aes_decryptor = true;
 
   concrete_key_systems->push_back(info);
 }
 
 class KeySystems {
  public:
   static KeySystems& GetInstance();
 
+  void UpdateIfNeeded();
+
   bool IsConcreteSupportedKeySystem(const std::string& key_system);
 
   bool IsSupportedKeySystemWithMediaMimeType(
       const std::string& mime_type,
       const std::vector<std::string>& codecs,
       const std::string& key_system);
 
   bool UseAesDecryptor(const std::string& concrete_key_system);
 
 #if defined(ENABLE_PEPPER_CDMS)
   std::string GetPepperType(const std::string& concrete_key_system);
 #endif
 
   void AddContainerMask(const std::string& container, uint32 mask);
   void AddCodecMask(const std::string& codec, uint32 mask);
 
  private:
+  void UpdateSupportedKeySystems();
+
   void AddConcreteSupportedKeySystems(
       const std::vector<KeySystemInfo>& concrete_key_systems);
 
   void AddConcreteSupportedKeySystem(
       const std::string& key_system,
       bool use_aes_decryptor,
 #if defined(ENABLE_PEPPER_CDMS)
       const std::string& pepper_type,
 #endif
       SupportedCodecs supported_codecs,
@@ skipping 37 matching lines @@
 
   // Map from parent key system to the concrete key system that should be used
   // to represent its capabilities.
   ParentKeySystemMap parent_key_system_map_;
 
   KeySystemsSupportUMA key_systems_support_uma_;
 
   CodecMaskMap container_codec_masks_;
   CodecMaskMap codec_masks_;
 
+  base::Time last_update_time_;
+
   DISALLOW_COPY_AND_ASSIGN(KeySystems);
 };
 
 static base::LazyInstance<KeySystems> g_key_systems = LAZY_INSTANCE_INITIALIZER;
 
 KeySystems& KeySystems::GetInstance() {
+  g_key_systems.Get().UpdateIfNeeded();
   return g_key_systems.Get();
 }
 
 // Because we use a LazyInstance, the key systems info must be populated when
 // the instance is lazily initiated.
 KeySystems::KeySystems() {
   // Build container and codec masks for quick look up.
   for (size_t i = 0; i < arraysize(kContainerCodecMasks); ++i) {
     const CodecMask& container_codec_mask = kContainerCodecMasks[i];
     DCHECK(container_codec_masks_.find(container_codec_mask.type) ==
            container_codec_masks_.end());
     container_codec_masks_[container_codec_mask.type] =
         container_codec_mask.mask;
   }
   for (size_t i = 0; i < arraysize(kCodecMasks); ++i) {
     const CodecMask& codec_mask = kCodecMasks[i];
     DCHECK(codec_masks_.find(codec_mask.type) == codec_masks_.end());
     codec_masks_[codec_mask.type] = codec_mask.mask;
   }
 
-  std::vector<KeySystemInfo> key_systems_info;
-  GetContentClient()->renderer()->AddKeySystems(&key_systems_info);
-  // Clear Key is always supported.
-  AddClearKey(&key_systems_info);
-  AddConcreteSupportedKeySystems(key_systems_info);
+  UpdateSupportedKeySystems();
+
 #if defined(WIDEVINE_CDM_AVAILABLE)
   key_systems_support_uma_.AddKeySystemToReport(kWidevineKeySystem);
 #endif  // defined(WIDEVINE_CDM_AVAILABLE)
 }
 
+void KeySystems::UpdateIfNeeded() {
+#if defined(WIDEVINE_CDM_AVAILABLE) && defined(WIDEVINE_CDM_IS_COMPONENT)
+  if (IsConcreteSupportedKeySystem(kWidevineKeySystem))
+    return;
+
+  // The update could involve a sync IPC to the browser process. Use a minimum
+  // update interval to avoid unnecessary frequent IPC to the browser.
+  static const int kMinUpdateIntervalInSeconds = 5;
+  base::Time now = base::Time::Now();
+  if (now - last_update_time_ <
+      base::TimeDelta::FromSeconds(kMinUpdateIntervalInSeconds)) {
+    return;
+  }
+
+  UpdateSupportedKeySystems();
+#endif
+}
+
+void KeySystems::UpdateSupportedKeySystems() {
+  DVLOG(2) << __FUNCTION__;

[xhwang, 2014/07/18 00:44:15]

I'll remove this.

+  concrete_key_system_map_.clear();
+  parent_key_system_map_.clear();
+
+  // Build KeySystemInfo.
+  std::vector<KeySystemInfo> key_systems_info;
+  GetContentClient()->renderer()->AddKeySystems(&key_systems_info);
+  // Clear Key is always supported.
+  AddClearKey(&key_systems_info);
+
+  AddConcreteSupportedKeySystems(key_systems_info);
+
+  last_update_time_ = base::Time::Now();
+}
+
 void KeySystems::AddConcreteSupportedKeySystems(
     const std::vector<KeySystemInfo>& concrete_key_systems) {
   for (size_t i = 0; i < concrete_key_systems.size(); ++i) {
     const KeySystemInfo& key_system_info = concrete_key_systems[i];
     AddConcreteSupportedKeySystem(key_system_info.key_system,
                                   key_system_info.use_aes_decryptor,
 #if defined(ENABLE_PEPPER_CDMS)
                                   key_system_info.pepper_type,
 #endif
                                   key_system_info.supported_codecs,
@@ skipping 244 matching lines @@
 CONTENT_EXPORT void AddContainerMask(const std::string& container,
                                      uint32 mask) {
   KeySystems::GetInstance().AddContainerMask(container, mask);
 }
 
 CONTENT_EXPORT void AddCodecMask(const std::string& codec, uint32 mask) {
   KeySystems::GetInstance().AddCodecMask(codec, mask);
 }
 
 }  // namespace content