[cast_channel] Make cast_channel related files not depend on "cast_channel.h"

extensions/browser/api/cast_channel/cast_framer.cc

 // Copyright 2014 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 "extensions/browser/api/cast_channel/cast_framer.h"
 
 #include <stdlib.h>
 
 #include <limits>
 
@@ skipping 101 matching lines @@
       return 0;
   }
 }
 
 std::unique_ptr<CastMessage> MessageFramer::Ingest(size_t num_bytes,
                                                    size_t* message_length,
                                                    ChannelError* error) {
   DCHECK(error);
   DCHECK(message_length);
   if (error_) {
-    *error = CHANNEL_ERROR_INVALID_MESSAGE;
+    *error = ChannelError::INVALID_MESSAGE;
     return nullptr;
   }
 
   DCHECK_EQ(base::checked_cast<int32_t>(message_bytes_received_),
             input_buffer_->offset());
   CHECK_LE(num_bytes, BytesRequested());
   message_bytes_received_ += num_bytes;
-  *error = CHANNEL_ERROR_NONE;
+  *error = ChannelError::NONE;
   *message_length = 0;
   switch (current_element_) {
     case HEADER:
       if (BytesRequested() == 0) {
         MessageHeader header;
         MessageHeader::Deserialize(input_buffer_->StartOfBuffer(), &header);
         if (header.message_size > MessageHeader::max_message_size()) {
           VLOG(1) << "Error parsing header (message size too large).";
-          *error = CHANNEL_ERROR_INVALID_MESSAGE;
+          *error = ChannelError::INVALID_MESSAGE;
           error_ = true;
           return nullptr;
         }
         current_element_ = BODY;
         body_size_ = header.message_size;
       }
       break;
     case BODY:
       if (BytesRequested() == 0) {
         std::unique_ptr<CastMessage> parsed_message(new CastMessage);
         if (!parsed_message->ParseFromArray(
                 input_buffer_->StartOfBuffer() + MessageHeader::header_size(),
                 body_size_)) {
           VLOG(1) << "Error parsing packet body.";
-          *error = CHANNEL_ERROR_INVALID_MESSAGE;
+          *error = ChannelError::INVALID_MESSAGE;
           error_ = true;
           return nullptr;
         }
         *message_length = body_size_;
         Reset();
         return parsed_message;
       }
       break;
     default:
       NOTREACHED() << "Unhandled packet element type.";
       return nullptr;
   }
 
   input_buffer_->set_offset(message_bytes_received_);
   return nullptr;
 }
 
 void MessageFramer::Reset() {
   current_element_ = HEADER;
   message_bytes_received_ = 0;
   body_size_ = 0;
   input_buffer_->set_offset(0);
 }
 
 }  // namespace cast_channel
 }  // namespace api
 }  // namespace extensions