Remove CDM_7 support

media/cdm/ppapi/ppapi_cdm_adapter.h

Index: media/cdm/ppapi/ppapi_cdm_adapter.h
diff --git a/media/cdm/ppapi/ppapi_cdm_adapter.h b/media/cdm/ppapi/ppapi_cdm_adapter.h
index 506dff7b74e2d2fe08daf1da580397691709451b..7f1f8016b14b73035309bca663c5b37a7264dff1 100644
--- a/media/cdm/ppapi/ppapi_cdm_adapter.h
+++ b/media/cdm/ppapi/ppapi_cdm_adapter.h
@@ -38,7 +38,6 @@ void* GetCdmHost(int host_interface_version, void* user_data);
 // Content Decryption Module (CDM).
 class PpapiCdmAdapter : public pp::Instance,
                         public pp::ContentDecryptor_Private,
-                        public cdm::Host_7,
                         public cdm::Host_8 {
  public:
   PpapiCdmAdapter(PP_Instance instance, pp::Module* module);
@@ -86,7 +85,7 @@ class PpapiCdmAdapter : public pp::Instance,
       pp::Buffer_Dev encrypted_buffer,
       const PP_EncryptedBlockInfo& encrypted_block_info) override;
 
-  // cdm::Host_7 and cdm::Host_8 implementation.
+  // cdm::Host_8 implementation.
   cdm::Buffer* Allocate(uint32_t capacity) override;
   void SetTimer(int64_t delay_ms, void* context) override;
   cdm::Time GetCurrentWallTime() override;