Fold the FWL NoteThread classes up to the Thread classes.

BUILD.gn

 # Copyright 2016 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_overrides/v8.gni")
 import("//testing/test.gni")
 import("pdfium.gni")
 
 config("pdfium_config") {
   cflags = []
@@ skipping 24 matching lines @@
   if (is_linux) {
     if (current_cpu == "x64") {
       defines += [ "_FX_CPU_=_FX_X64_" ]
       cflags += [ "-fPIC" ]
     } else if (current_cpu == "x86") {
       defines += [ "_FX_CPU_=_FX_X86_" ]
     }
   }
 
   if (is_win) {
-    cflags += [
-      "/wd4267",
-    ]
+    cflags += [ "/wd4267" ]
   }
 
   if (is_clang || is_posix) {
     # TODO(thestig): Fix all instances, remove this, pdfium:29
     cflags += [ "-Wno-sign-compare" ]
   }
 
   if (is_posix && !is_clang) {  # When GCC.
     cflags += [ "-Wno-error=strict-overflow" ]
   }
@@ skipping 1004 matching lines @@
       "xfa/fwl/core/ifwl_adapterthreadmgr.h",
       "xfa/fwl/core/ifwl_adapterwidgetmgr.h",
       "xfa/fwl/core/ifwl_app.h",
       "xfa/fwl/core/ifwl_content.h",
       "xfa/fwl/core/ifwl_custom.h",
       "xfa/fwl/core/ifwl_custompanel.h",
       "xfa/fwl/core/ifwl_dataprovider.h",
       "xfa/fwl/core/ifwl_form.h",
       "xfa/fwl/core/ifwl_notedriver.h",
       "xfa/fwl/core/ifwl_noteloop.h",
-      "xfa/fwl/core/ifwl_notethread.h",
       "xfa/fwl/core/ifwl_panel.h",
       "xfa/fwl/core/ifwl_proxy.h",
       "xfa/fwl/core/ifwl_target.h",
       "xfa/fwl/core/ifwl_themeprovider.h",
       "xfa/fwl/core/ifwl_thread.h",
       "xfa/fwl/core/ifwl_timer.h",
       "xfa/fwl/core/ifwl_tooltiptarget.h",
       "xfa/fwl/core/ifwl_widget.h",
       "xfa/fwl/core/ifwl_widgetdelegate.h",
       "xfa/fwl/core/ifwl_widgetmgr.h",
@@ skipping 642 matching lines @@
       "//v8:v8_libplatform",
     ]
     include_dirs += [
       "//v8",
       "//v8/include",
     ]
     configs += [ "//v8:external_startup_data" ]
   }
   configs += [ ":pdfium_config" ]
 }