Allow suppressed EME canPlayType() responses to be overridden with a flag.

webkit/renderer/media/crypto/key_systems_info.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 "webkit/renderer/media/crypto/key_systems_info.h"
 
 #include "widevine_cdm_version.h" // In SHARED_INTERMEDIATE_DIR.
 
+// The following must be after widevine_cdm_version.h.
+
 #if defined(WIDEVINE_CDM_AVAILABLE) && \
     defined(OS_LINUX) && !defined(OS_CHROMEOS)
 #include <gnu/libc-version.h>
 #include "base/logging.h"
 #include "base/version.h"
 #endif
 
+#if defined(DISABLE_WIDEVINE_CDM_CANPLAYTYPE)
+#include "base/command_line.h"
+#include "media/base/media_switches.h"
+#endif
+
 namespace webkit_media {
 
 static const char kClearKeyKeySystem[] = "webkit-org.w3.clearkey";
 
 static const char kExternalClearKeyKeySystem[] =
     "org.chromium.externalclearkey";
 
 #if defined(WIDEVINE_CDM_AVAILABLE)
 // TODO(ddorwin): Automatically support parent systems: http://crbug.com/164303.
 static const char kWidevineBaseKeySystem[] = "com.widevine";
-#endif  // defined(WIDEVINE_CDM_AVAILABLE)
 
 #if defined(WIDEVINE_CDM_CENC_SUPPORT_AVAILABLE)
 // The supported codecs depend on what the CDM provides.
 static const char kWidevineVideoMp4Codecs[] =
 #if defined(WIDEVINE_CDM_AVC1_SUPPORT_AVAILABLE) && \
     defined(WIDEVINE_CDM_AAC_SUPPORT_AVAILABLE)
     "avc1,mp4a";
 #elif defined(WIDEVINE_CDM_AVC1_SUPPORT_AVAILABLE)
     "avc1";
 #else
     "";  // No codec strings are supported.
 #endif
 
 static const char kWidevineAudioMp4Codecs[] =
 #if defined(WIDEVINE_CDM_AAC_SUPPORT_AVAILABLE)
     "mp4a";
 #else
     "";  // No codec strings are supported.
 #endif
 #endif  // defined(WIDEVINE_CDM_CENC_SUPPORT_AVAILABLE)
 
+static inline bool IsWidevine(const std::string& key_system) {
+  return key_system == kWidevineKeySystem ||
+         key_system == kWidevineBaseKeySystem;
+}
+#endif  // defined(WIDEVINE_CDM_AVAILABLE)
+
 const MediaFormatAndKeySystem kSupportedFormatKeySystemCombinations[] = {
   // Clear Key.
   { "video/webm", "vorbis,vp8,vp8.0", kClearKeyKeySystem },
   { "audio/webm", "vorbis", kClearKeyKeySystem },
 #if defined(GOOGLE_CHROME_BUILD) || defined(USE_PROPRIETARY_CODECS)
   { "video/mp4", "avc1,mp4a", kClearKeyKeySystem },
   { "audio/mp4", "mp4a", kClearKeyKeySystem },
 #endif
 
   // External Clear Key (used for testing).
   { "video/webm", "vorbis,vp8,vp8.0", kExternalClearKeyKeySystem },
   { "audio/webm", "vorbis", kExternalClearKeyKeySystem },
 #if defined(GOOGLE_CHROME_BUILD) || defined(USE_PROPRIETARY_CODECS)
   { "video/mp4", "avc1,mp4a", kExternalClearKeyKeySystem },
   { "audio/mp4", "mp4a", kExternalClearKeyKeySystem },
 #endif
 
 #if defined(WIDEVINE_CDM_AVAILABLE)
   // Widevine.
-  // See http://crbug.com/237627.
-#if defined(DISABLE_WIDEVINE_CDM_CANPLAYTYPE)
-  { "", "", kWidevineKeySystem },
-#else
   { "video/webm", "vorbis,vp8,vp8.0", kWidevineKeySystem },
   { "audio/webm", "vorbis", kWidevineKeySystem },
   { "video/webm", "vorbis,vp8,vp8.0", kWidevineBaseKeySystem },
   { "audio/webm", "vorbis", kWidevineBaseKeySystem },
 #if defined(GOOGLE_CHROME_BUILD) || defined(USE_PROPRIETARY_CODECS)
 #if defined(WIDEVINE_CDM_CENC_SUPPORT_AVAILABLE)
   { "video/mp4", kWidevineVideoMp4Codecs, kWidevineKeySystem },
   { "video/mp4", kWidevineVideoMp4Codecs, kWidevineBaseKeySystem },
   { "audio/mp4", kWidevineAudioMp4Codecs, kWidevineKeySystem },
   { "audio/mp4", kWidevineAudioMp4Codecs, kWidevineBaseKeySystem },
 #endif  // defined(WIDEVINE_CDM_CENC_SUPPORT_AVAILABLE)
 #endif  // defined(GOOGLE_CHROME_BUILD) || defined(USE_PROPRIETARY_CODECS)
-#endif  // defined(DISABLE_WIDEVINE_CDM_CANPLAYTYPE)
 #endif  // WIDEVINE_CDM_AVAILABLE
 };
 
 const int kNumSupportedFormatKeySystemCombinations =
     arraysize(kSupportedFormatKeySystemCombinations);
 
 #if defined(ENABLE_PEPPER_CDMS)
 const KeySystemPepperTypePair kKeySystemToPepperTypeMapping[] = {
   { kExternalClearKeyKeySystem, "application/x-ppapi-clearkey-cdm"},
 #if defined(WIDEVINE_CDM_AVAILABLE)
@@ skipping 16 matching lines @@
 };
 
 // arraySize() does not work if the array is empty, so use ARRAYSIZE_UNSAFE().
 const int kNumKeySystemToUUIDMapping =
     ARRAYSIZE_UNSAFE(kKeySystemToUUIDMapping);
 #endif  // defined(OS_ANDROID)
 
 bool IsSystemCompatible(const std::string& key_system) {
 #if defined(WIDEVINE_CDM_AVAILABLE) && \
     defined(OS_LINUX) && !defined(OS_CHROMEOS)
-  if (key_system == kWidevineKeySystem ||
-      key_system == kWidevineBaseKeySystem) {
+  if (IsWidevine(key_system)) {
     Version glibc_version(gnu_get_libc_version());
     DCHECK(glibc_version.IsValid());
     return !glibc_version.IsOlderThan(WIDEVINE_CDM_MIN_GLIBC_VERSION);
   }
 #endif
   return true;
 }
 
+bool IsCanPlayTypeSuppressed(const std::string& key_system) {
+#if defined(DISABLE_WIDEVINE_CDM_CANPLAYTYPE)
+  // See http://crbug.com/237627.
+  if (IsWidevine(key_system) &&
+      !CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kEncryptedMediaCanPlayTypeOverride))
+    return true;
+#endif
+  return false;
+}
+
 std::string KeySystemNameForUMAGeneric(const std::string& key_system) {
   if (key_system == kClearKeyKeySystem)
     return "ClearKey";
 #if defined(WIDEVINE_CDM_AVAILABLE)
   if (key_system == kWidevineKeySystem)
     return "Widevine";
 #endif  // WIDEVINE_CDM_AVAILABLE
   return "Unknown";
 }
 
 bool CanUseBuiltInAesDecryptor(const std::string& key_system) {
   return  key_system == kClearKeyKeySystem;
 }
 
 } // namespace webkit_media