Remove obsolete OS handling in GN.

tools/gn/ninja_binary_target_writer.cc

 // Copyright (c) 2013 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 "tools/gn/ninja_binary_target_writer.h"
 
 #include <cstring>
 #include <set>
 #include <sstream>
 
@@ skipping 842 matching lines @@
 
 void NinjaBinaryTargetWriter::WriteLibs() {
   out_ << "  libs =";
 
   // Libraries that have been recursively pushed through the dependency tree.
   EscapeOptions lib_escape_opts;
   lib_escape_opts.mode = ESCAPE_NINJA_COMMAND;
   const OrderedSet<std::string> all_libs = target_->all_libs();
   const std::string framework_ending(".framework");
   for (size_t i = 0; i < all_libs.size(); i++) {
-    if (settings_->IsMac() &&
-        base::EndsWith(all_libs[i], framework_ending,
+    if (base::EndsWith(all_libs[i], framework_ending,
                        base::CompareCase::INSENSITIVE_ASCII)) {
-      // Special-case libraries ending in ".framework" on Mac. Add the
+      // Special-case libraries ending in ".framework" to support Mac: Add the
       // -framework switch and don't add the extension to the output.
       out_ << " -framework ";
       EscapeStringToStream(out_,
           all_libs[i].substr(0, all_libs[i].size() - framework_ending.size()),
           lib_escape_opts);
     } else {
       out_ << " " << tool_->lib_switch();
       EscapeStringToStream(out_, all_libs[i], lib_escape_opts);
     }
   }
@@ skipping 151 matching lines @@
           "\n"
           "In the latter case, either rename one of the files or move one of\n"
           "the sources to a separate source_set to avoid them both being in\n"
           "the same target.");
       g_scheduler->FailWithError(err);
       return false;
     }
   }
   return true;
 }