Remove indexed_db_messages.h.

content/common/BUILD.gn

 # 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.
 
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//media/media_options.gni")
 import("//mojo/public/tools/bindings/mojom.gni")
 import("//ppapi/features/features.gni")
 import("//sandbox/features.gni")
@@ skipping 124 matching lines @@
     "in_process_child_thread_params.h",
     "indexed_db/indexed_db_constants.h",
     "indexed_db/indexed_db_enum_traits.cc",
     "indexed_db/indexed_db_enum_traits.h",
     "indexed_db/indexed_db_key.cc",
     "indexed_db/indexed_db_key.h",
     "indexed_db/indexed_db_key_path.cc",
     "indexed_db/indexed_db_key_path.h",
     "indexed_db/indexed_db_key_range.cc",
     "indexed_db/indexed_db_key_range.h",
-    "indexed_db/indexed_db_messages.h",
     "indexed_db/indexed_db_metadata.cc",
     "indexed_db/indexed_db_metadata.h",
     "indexed_db/indexed_db_struct_traits.cc",
     "indexed_db/indexed_db_struct_traits.h",
     "input/event_with_latency_info.cc",
     "input/event_with_latency_info.h",
     "input/gesture_event_stream_validator.cc",
     "input/gesture_event_stream_validator.h",
     "input/input_event.cc",
     "input/input_event.h",
@@ skipping 447 matching lines @@
     "//ui/gfx/geometry/mojo",
     "//ui/gfx/mojo",
     "//url/mojo:url_mojom_gurl",
     "//url/mojo:url_mojom_origin",
   ]
 
   export_class_attribute = "CONTENT_EXPORT"
   export_define = "CONTENT_IMPLEMENTATION=1"
   export_header = "content/common/content_export.h"
 }