Move ContentDecryptionModule* to platform/

Source/platform/drm/ContentDecryptionModule.h

Index: Source/platform/drm/ContentDecryptionModule.h
diff --git a/Source/core/platform/graphics/ContentDecryptionModule.h b/Source/platform/drm/ContentDecryptionModule.h
similarity index 96%
rename from Source/core/platform/graphics/ContentDecryptionModule.h
rename to Source/platform/drm/ContentDecryptionModule.h
index 3fe04049cfa01c43f71fa272f746f2bda190bc2d..2a1fc8cd45d7f0ecaeecf3605645395ec5114529 100644
--- a/Source/core/platform/graphics/ContentDecryptionModule.h
+++ b/Source/platform/drm/ContentDecryptionModule.h
@@ -31,6 +31,7 @@
 #ifndef ContentDecryptionModule_h
 #define ContentDecryptionModule_h
 
+#include "platform/PlatformExport.h"
 #include "public/platform/WebContentDecryptionModule.h"
 #include "wtf/OwnPtr.h"
 #include "wtf/PassOwnPtr.h"
@@ -41,7 +42,7 @@ namespace WebCore {
 class ContentDecryptionModuleSession;
 class ContentDecryptionModuleSessionClient;
 
-class ContentDecryptionModule {
+class PLATFORM_EXPORT ContentDecryptionModule {
 public:
     static bool supportsKeySystem(const String&);
     static PassOwnPtr<ContentDecryptionModule> create(const String& keySystem);