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

webkit/renderer/media/crypto/key_systems_info.cc

Index: webkit/renderer/media/crypto/key_systems_info.cc
diff --git a/webkit/renderer/media/crypto/key_systems_info.cc b/webkit/renderer/media/crypto/key_systems_info.cc
index 9810c349eaa4baa9b47d72cee3ade5e82935b880..ae322e4bc6d2ad4de989ce6030f8489bf32d8a76 100644
--- a/webkit/renderer/media/crypto/key_systems_info.cc
+++ b/webkit/renderer/media/crypto/key_systems_info.cc
@@ -6,6 +6,8 @@
 
 #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>
@@ -13,6 +15,11 @@
 #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";
@@ -23,7 +30,6 @@ static const char kExternalClearKeyKeySystem[] =
 #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.
@@ -45,6 +51,12 @@ static const char kWidevineAudioMp4Codecs[] =
 #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 },
@@ -64,10 +76,6 @@ const MediaFormatAndKeySystem kSupportedFormatKeySystemCombinations[] = {
 
 #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 },
@@ -80,7 +88,6 @@ const MediaFormatAndKeySystem kSupportedFormatKeySystemCombinations[] = {
   { "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
 };
 
@@ -117,8 +124,7 @@ const int kNumKeySystemToUUIDMapping =
 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);
@@ -127,6 +133,17 @@ bool IsSystemCompatible(const std::string& key_system) {
   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";