Rename CPDFSDK_Environment to CPDFSDK_FormfillEnvironment

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_common_config") {
   cflags = []
@@ skipping 62 matching lines @@
     "fpdfsdk/cpdfsdk_annotiterator.cpp",
     "fpdfsdk/cpdfsdk_annotiterator.h",
     "fpdfsdk/cpdfsdk_baannot.cpp",
     "fpdfsdk/cpdfsdk_baannot.h",
     "fpdfsdk/cpdfsdk_baannothandler.cpp",
     "fpdfsdk/cpdfsdk_baannothandler.h",
     "fpdfsdk/cpdfsdk_datetime.cpp",
     "fpdfsdk/cpdfsdk_datetime.h",
     "fpdfsdk/cpdfsdk_document.cpp",
     "fpdfsdk/cpdfsdk_document.h",
-    "fpdfsdk/cpdfsdk_environment.cpp",
-    "fpdfsdk/cpdfsdk_environment.h",
+    "fpdfsdk/cpdfsdk_formfillenvironment.cpp",
+    "fpdfsdk/cpdfsdk_formfillenvironment.h",
     "fpdfsdk/cpdfsdk_interform.cpp",
     "fpdfsdk/cpdfsdk_interform.h",
     "fpdfsdk/cpdfsdk_pageview.cpp",
     "fpdfsdk/cpdfsdk_pageview.h",
     "fpdfsdk/cpdfsdk_widget.cpp",
     "fpdfsdk/cpdfsdk_widget.h",
     "fpdfsdk/cpdfsdk_widgethandler.cpp",
     "fpdfsdk/cpdfsdk_widgethandler.h",
     "fpdfsdk/fpdf_dataavail.cpp",
     "fpdfsdk/fpdf_ext.cpp",
@@ skipping 1661 matching lines @@
 }
 
 if (pdf_is_standalone) {
   source_set("samples") {
     testonly = true
     deps = [
       "//samples",
     ]
   }
 }