Add support for /DEBUG:FASTLINK to gyp and gn files.

build/config/compiler/BUILD.gn

 # 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.
 
 import("//build/config/android/config.gni")
 import("//build/config/chrome_build.gni")
 if (current_cpu == "arm") {
   import("//build/config/arm.gni")
 }
 if (current_cpu == "mipsel" || current_cpu == "mips64el") {
@@ skipping 128 matching lines @@
         cflags += [
           # cmd.exe doesn't understand ANSI escape codes by default,
           # so only enable them if something emulating them is around.
           "-fansi-escape-codes",
         ]
       }
     }
 
     if (is_syzyasan) {
       # SyzyAsan needs /PROFILE turned on to produce appropriate pdbs.
+      assert(!is_win_fastlink, "/PROFILE and /DEBUG:FASTLINK are incompatible")
       ldflags += [ "/PROFILE" ]
     }
   } else {
     # Common GCC compiler flags setup.
     # --------------------------------
     cflags += [ "-fno-strict-aliasing" ]  # See http://crbug.com/32204
     cflags_cc += [
       "-fno-threadsafe-statics",
 
       # Not exporting C++ inline functions can generally be applied anywhere
@@ skipping 1079 matching lines @@
 # Symbols ----------------------------------------------------------------------
 
 config("symbols") {
   if (is_win) {
     import("//build/toolchain/goma.gni")
     if (use_goma) {
       cflags = [ "/Z7" ]  # No PDB file
     } else {
       cflags = [ "/Zi" ]  # Produce PDB file, no edit and continue.
     }
-    ldflags = [ "/DEBUG" ]
+    if (is_win_fastlink) {
+      # Tell VS 2015+ to create a PDB that references debug
+      # information in .obj and .lib files instead of copying
+      # it all. This flag is incompatible with /PROFILE
+      ldflags = [ "/DEBUG:FASTLINK" ]
+    } else {
+      ldflags = [ "/DEBUG" ]
+    }
   } else {
     cflags = [ "-g2" ]
     if (use_debug_fission) {
       cflags += [ "-gsplit-dwarf" ]
     }
   }
 }
 
 config("minimal_symbols") {
   if (is_win) {
     # Linker symbols for backtraces only.
-    ldflags = [ "/DEBUG" ]
+    if (is_win_fastlink) {
+      # Tell VS 2015+ to create a PDB that references debug
+      # information in .obj and .lib files instead of copying
+      # it all. This flag is incompatible with /PROFILE
+      ldflags = [ "/DEBUG:FASTLINK" ]
+    } else {
+      ldflags = [ "/DEBUG" ]
+    }
   } else {
     cflags = [ "-g1" ]
     if (use_debug_fission) {
       cflags += [ "-gsplit-dwarf" ]
     }
   }
 }
 
 config("no_symbols") {
   if (!is_win) {
     cflags = [ "-g0" ]
   }
 }