Handle CdmWrapper::Initialize() failure gracefully.

Since CdmWrapper::Initialize() doesn't report error, GenerateKeyRequest() et al
can be called even if Initialize() failed previously.

For MediaKeys calls, we should fire KeyError when they are called without valid
|cdm_|. For Decryptor calls, we should fire the callback with error code.

Also added EncryptedMediaTest.ExternalClearKeyInitializeCDMFail test to cover
this case. Chrome will claim that the ClearKey CDM supports key system
"org.chromium.externalclearkey.fail". But actually ClearKey CDM will return NULL
for this key system in CreateCdmInstance();

BUG=306241,179570
TEST=Unit tests added.

Review URL: https://codereview.chromium.org/27030007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@228528 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 43 insertions, 22 deletions

diff --git a/chrome/browser/media/encrypted_media_browsertest.cc b/chrome/browser/media/encrypted_media_browsertest.cc
index 850d16c..e1e68aa 100644
--- a/chrome/browser/media/encrypted_media_browsertest.cc
+++ b/chrome/browser/media/encrypted_media_browsertest.cc
@@ -306,3 +306,14 @@ IN_PROC_BROWSER_TEST_F(EncryptedMediaTest, WVParentThrowsException) {
                         kWebMAudioOnly, "com.widevine", SRC, kEmeGkrException);
 }
 #endif  // defined(WIDEVINE_CDM_AVAILABLE)
+
+#if defined(ENABLE_PEPPER_CDMS)
+IN_PROC_BROWSER_TEST_F(EncryptedMediaTest, ExternalClearKeyInitializeCDMFail) {
+  RunEncryptedMediaTest("encrypted_media_player.html",
+                        "bear-a-enc_a.webm",
+                        kWebMAudioOnly,
+                        "org.chromium.externalclearkey.initializefail",
+                        SRC,
+                        kEmeKeyError);
+}
+#endif  // defined(ENABLE_PEPPER_CDMS)
diff --git a/chrome/renderer/media/chrome_key_systems.cc b/chrome/renderer/media/chrome_key_systems.cc
index 014035d..12dfa92 100644
--- a/chrome/renderer/media/chrome_key_systems.cc
+++ b/chrome/renderer/media/chrome_key_systems.cc
@@ -69,10 +69,15 @@ static void AddExternalClearKey(
   info.supported_types.push_back(std::make_pair(kAudioMp4, kMp4a));
   info.supported_types.push_back(std::make_pair(kVideoMp4, kMp4aAvc1));
 #endif  // defined(USE_PROPRIETARY_CODECS)
-
   info.pepper_type = kExternalClearKeyPepperType;
 
   concrete_key_systems->push_back(info);
+
+  // A key system that Chrome thinks is supported by ClearKeyCdm, but actually
+  // will be refused by ClearKeyCdm. This is to test the CDM initialization
+  // failure case.
+  info.key_system += ".initializefail";
+  concrete_key_systems->push_back(info);
 }
 #endif  // defined(ENABLE_PEPPER_CDMS)
 
diff --git a/media/cdm/ppapi/cdm_wrapper.cc b/media/cdm/ppapi/cdm_wrapper.cc
index 6d8a788..60a8e44 100644
--- a/media/cdm/ppapi/cdm_wrapper.cc
+++ b/media/cdm/ppapi/cdm_wrapper.cc
@@ -586,6 +586,7 @@ class CdmWrapper : public pp::Instance,
   void SendKeyAdded(const std::string& key_system,
                     const std::string& session_id);
 
+  // TODO(jrummell): Drop the |key_system| parameter.
   void SendKeyErrorInternal(const std::string& key_system,
                             const std::string& session_id,
                             cdm::MediaKeyError error_code,
@@ -707,25 +708,29 @@ bool CdmWrapper::CreateCdmInstance(const std::string& key_system) {
   return (cdm_ != NULL);
 }
 
+// No KeyErrors should be reported in this function because they cannot be
+// bubbled up in the WD EME API. Those errors will be reported during session
+// creation (aka GenerateKeyRequest).
 void CdmWrapper::Initialize(const std::string& key_system,
                             bool can_challenge_platform) {
   PP_DCHECK(!key_system.empty());
   PP_DCHECK(key_system_.empty() || (key_system_ == key_system && cdm_));
 
-  if (!cdm_) {
-    if (!CreateCdmInstance(key_system)) {
-      // TODO(jrummell): Is UnknownKeyError the correct response?
-      SendUnknownKeyError(key_system, std::string());
-      return;
-    }
-  }
+  if (!cdm_ && !CreateCdmInstance(key_system))
+    return;
+
   PP_DCHECK(cdm_);
   key_system_ = key_system;
 }
 
 void CdmWrapper::GenerateKeyRequest(const std::string& type,
                                     pp::VarArrayBuffer init_data) {
-  PP_DCHECK(cdm_);  // Initialize() should have succeeded.
+  // Initialize() doesn't report an error, so GenerateKeyRequest() can be called
+  // even if Initialize() failed.
+  if (!cdm_) {
+    SendUnknownKeyError(key_system_, std::string());
+    return;
+  }
 
 #if defined(CHECK_DOCUMENT_URL)
   PP_URLComponents_Dev url_components = {};
@@ -749,7 +754,8 @@ void CdmWrapper::GenerateKeyRequest(const std::string& type,
 void CdmWrapper::AddKey(const std::string& session_id,
                         pp::VarArrayBuffer key,
                         pp::VarArrayBuffer init_data) {
-  PP_DCHECK(cdm_);  // Initialize() should have succeeded.
+  // TODO(jrummell): In EME WD, AddKey() can only be called on valid sessions.
+  // We should be able to DCHECK(cdm_) when addressing http://crbug.com/249976.
   if (!cdm_) {
     SendUnknownKeyError(key_system_, session_id);
     return;
@@ -779,7 +785,8 @@ void CdmWrapper::AddKey(const std::string& session_id,
 }
 
 void CdmWrapper::CancelKeyRequest(const std::string& session_id) {
-  PP_DCHECK(cdm_);  // Initialize() should have succeeded.
+  // TODO(jrummell): In EME WD, AddKey() can only be called on valid sessions.
+  // We should be able to DCHECK(cdm_) when addressing http://crbug.com/249976.
   if (!cdm_) {
     SendUnknownKeyError(key_system_, session_id);
     return;
@@ -797,7 +804,6 @@ void CdmWrapper::CancelKeyRequest(const std::string& session_id) {
 
 void CdmWrapper::Decrypt(pp::Buffer_Dev encrypted_buffer,
                          const PP_EncryptedBlockInfo& encrypted_block_info) {
-  PP_DCHECK(cdm_);  // Initialize() should have succeeded.
   PP_DCHECK(!encrypted_buffer.is_null());
 
   // Release a buffer that the caller indicated it is finished with.
@@ -827,8 +833,6 @@ void CdmWrapper::Decrypt(pp::Buffer_Dev encrypted_buffer,
 void CdmWrapper::InitializeAudioDecoder(
     const PP_AudioDecoderConfig& decoder_config,
     pp::Buffer_Dev extra_data_buffer) {
-  PP_DCHECK(cdm_);  // Initialize() should have succeeded.
-
   cdm::Status status = cdm::kSessionError;
   if (cdm_) {
     cdm::AudioDecoderConfig cdm_decoder_config;
@@ -854,8 +858,6 @@ void CdmWrapper::InitializeAudioDecoder(
 void CdmWrapper::InitializeVideoDecoder(
     const PP_VideoDecoderConfig& decoder_config,
     pp::Buffer_Dev extra_data_buffer) {
-  PP_DCHECK(cdm_);  // Initialize() should have succeeded.
-
   cdm::Status status = cdm::kSessionError;
   if (cdm_) {
     cdm::VideoDecoderConfig cdm_decoder_config;
@@ -883,7 +885,7 @@ void CdmWrapper::InitializeVideoDecoder(
 
 void CdmWrapper::DeinitializeDecoder(PP_DecryptorStreamType decoder_type,
                                      uint32_t request_id) {
-  PP_DCHECK(cdm_);  // Initialize() should have succeeded.
+  PP_DCHECK(cdm_);  // InitializeXxxxxDecoder should have succeeded.
   if (cdm_) {
     cdm_->DeinitializeDecoder(
         PpDecryptorStreamTypeToCdmStreamType(decoder_type));
@@ -897,7 +899,7 @@ void CdmWrapper::DeinitializeDecoder(PP_DecryptorStreamType decoder_type,
 
 void CdmWrapper::ResetDecoder(PP_DecryptorStreamType decoder_type,
                               uint32_t request_id) {
-  PP_DCHECK(cdm_);  // Initialize() should have succeeded.
+  PP_DCHECK(cdm_);  // InitializeXxxxxDecoder should have succeeded.
   if (cdm_)
     cdm_->ResetDecoder(PpDecryptorStreamTypeToCdmStreamType(decoder_type));
 
@@ -910,8 +912,7 @@ void CdmWrapper::DecryptAndDecode(
     PP_DecryptorStreamType decoder_type,
     pp::Buffer_Dev encrypted_buffer,
     const PP_EncryptedBlockInfo& encrypted_block_info) {
-  PP_DCHECK(cdm_);  // Initialize() should have succeeded.
-
+  PP_DCHECK(cdm_);  // InitializeXxxxxDecoder should have succeeded.
   // Release a buffer that the caller indicated it is finished with.
   allocator_.Release(encrypted_block_info.tracking_info.buffer_id);
 
@@ -1027,7 +1028,6 @@ void CdmWrapper::SendKeyErrorInternal(const std::string& key_system,
                                       const std::string& session_id,
                                       cdm::MediaKeyError error_code,
                                       uint32_t system_code) {
-  PP_DCHECK(!key_system.empty());
   PostOnMain(callback_factory_.NewCallback(&CdmWrapper::KeyError,
                                            SessionInfo(key_system_, session_id),
                                            error_code,
@@ -1063,7 +1063,6 @@ void CdmWrapper::KeyError(int32_t result,
                           cdm::MediaKeyError error_code,
                           uint32_t system_code) {
   PP_DCHECK(result == PP_OK);
-  PP_DCHECK(!session_info.key_system.empty());
   pp::ContentDecryptor_Private::KeyError(
       session_info.key_system, session_info.session_id,
       error_code, system_code);
diff --git a/media/cdm/ppapi/clear_key_cdm.cc b/media/cdm/ppapi/clear_key_cdm.cc
index d6702ca..6ab0773 100644
--- a/media/cdm/ppapi/clear_key_cdm.cc
+++ b/media/cdm/ppapi/clear_key_cdm.cc
@@ -60,6 +60,7 @@ static bool g_ffmpeg_lib_initialized = InitializeFFmpegLibraries();
 #endif  // CLEAR_KEY_CDM_USE_FFMPEG_DECODER
 
 const char kClearKeyCdmVersion[] = "0.1.0.1";
+const char kExternalClearKeyKeySystem[] = "org.chromium.externalclearkey";
 const int64 kSecondsPerMinute = 60;
 const int64 kMsPerSecond = 1000;
 const int64 kInitialTimerDelayMs = 200;
@@ -130,6 +131,11 @@ void* CreateCdmInstance(
     GetCdmHostFunc get_cdm_host_func, void* user_data) {
   DVLOG(1) << "CreateCdmInstance()";
 
+  if (std::string(key_system, key_system_size) != kExternalClearKeyKeySystem) {
+    DVLOG(1) << "Unsupported key system.";
+    return NULL;
+  }
+
   if (cdm_interface_version != cdm::kCdmInterfaceVersion)
     return NULL;