Update from https://crrev.com/320343

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")
 if (current_cpu == "arm") {
   import("//build/config/arm.gni")
 }
 if (current_cpu == "mipsel" || current_cpu == "mips64el") {
   import("//build/config/mips.gni")
@@ skipping 60 matching lines @@
 
 # TODO(GYP): is_ubsan, is_ubsan_vptr
 if (!is_win) {
   using_sanitizer = is_asan || is_lsan || is_tsan || is_msan
 }
 
 # compiler ---------------------------------------------------------------------
 #
 # Base compiler configuration.
 #
-# See also "runtime_library" below for related stuff and a discusison about
+# See also "runtime_library" below for related stuff and a discussion about
 # where stuff should go. Put warning related stuff in the "warnings" config.
 
 config("compiler") {
   cflags = []
   cflags_c = []
   cflags_cc = []
   ldflags = []
   defines = []
 
   # In general, Windows is totally different, but all the other builds share
   # some common GCC configuration. This section sets up Windows and the common
   # GCC flags, and then we handle the other non-Windows platforms specifically
   # below.
   if (is_win) {
     # Windows compiler flags setup.
     # -----------------------------
     cflags += [
       "/Gy",  # Enable function-level linking.
       "/GS",  # Enable buffer security checking.
       "/FS",  # Preserve previous PDB behavior.
     ]
-    if (is_component_build) {
-      cflags += [ "/EHsc" ]  # Assume C functions can't throw exceptions and don't catch
-                             # structured exceptions (only C++ ones).
-    }
   } 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
       # so we do so here. Normal function visibility is controlled by
       # //build/config/gcc:symbol_visibility_hidden.
@@ skipping 37 matching lines @@
     # Allow comparing the address of references and 'this' against 0
     # in debug builds. Technically, these can never be null in
     # well-defined C/C++ and Clang can optimize such checks away in
     # release builds, but they may be used in asserts in debug builds.
     cflags_cc += [
       "-Wno-undefined-bool-conversion",
       "-Wno-tautological-undefined-compare",
     ]
   }
 
-  if (is_clang && !is_win) {
+  if (is_clang && !is_win && !is_nacl) {
     # This is here so that all files get recompiled after a clang roll and
     # when turning clang on or off. (defines are passed via the command line,
     # and build system rebuild things when their commandline changes). Nothing
     # should ever read this define.
     defines += [ "CR_CLANG_REVISION=" +
                  exec_script("//tools/clang/scripts/posix-print-revision.py",
                              [],
                              "value") ]
   }
 
@@ skipping 221 matching lines @@
       # Experimentation found that using four linking threads
       # saved ~20% of link time.
       # https://groups.google.com/a/chromium.org/group/chromium-dev/browse_thread/thread/281527606915bb36
       # Only apply this to the target linker, since the host
       # linker might not be gold, but isn't used much anyway.
       # TODO(raymes): Disable threading because gold is frequently
       # crashing on the bots: crbug.com/161942.
       #"-Wl,--threads",
       #"-Wl,--thread-count=4",
     ]
+
+    # TODO(thestig): Make this flag work with GN.
+    #if (!is_official_build && !is_chromeos && !(is_asan || is_lsan || is_tsan || is_msan)) {
+    #  ldflags += [
+    #    "-Wl,--detect-odr-violations",
+    #  ]
+    #}
   }
 
   if (linux_use_bundled_binutils) {
     binutils_path = rebase_path("//third_party/binutils/Linux_x64/Release/bin",
                                 root_build_dir)
     cflags += [ "-B$binutils_path" ]
   }
 
   # Clang-specific compiler flags setup.
   # ------------------------------------
@@ skipping 111 matching lines @@
       # about things not matching, so keep exceptions on.
       if (is_debug) {
         cflags += [ "/MDd" ]
       } else {
         cflags += [ "/MD" ]
       }
     }
   } else {
     # Static CRT.
     if (is_win) {
-      # We don't use exceptions, and when we link statically we can just get
-      # rid of them entirely.
-      defines += [ "_HAS_EXCEPTIONS=0" ]
       if (is_debug) {
         cflags += [ "/MTd" ]
       } else {
         cflags += [ "/MT" ]
       }
     }
   }
 
   if (is_win) {
     defines += [
       "__STD_C",
-      "__STDC_CONSTANT_MACROS",
-      "__STDC_FORMAT_MACROS",
       "_CRT_RAND_S",
       "_CRT_SECURE_NO_DEPRECATE",
+      "_HAS_EXCEPTIONS=0",
       "_SCL_SECURE_NO_DEPRECATE",
     ]
   }
 
   # Stlport setup. Android uses a different (smaller) version of the STL.
   if (is_android) {
     if (is_clang) {
       # Work around incompatibilities between bionic and clang headers.
       defines += [
         "__compiler_offsetof=__builtin_offsetof",
@@ skipping 155 matching lines @@
 
 # Warnings ---------------------------------------------------------------------
 #
 # This is where we disable various warnings that we've decided aren't
 # worthwhile, and enable special warnings.
 
 config("default_warnings") {
   if (is_win) {
     cflags = [
       "/WX",  # Treat warnings as errors.
-
       # Warnings permanently disabled:
 
       # TODO(GYP) The GYP build doesn't have this globally enabled but disabled
       # for a bunch of individual targets. Re-enable this globally when those
       # targets are fixed.
       "/wd4018",  # Comparing signed and unsigned values.
 
       # C4127: conditional expression is constant
       # This warning can in theory catch dead code and other problems, but
       # triggers in far too many desirable cases where the conditional
@@ skipping 34 matching lines @@
 
       # C4611: interaction between 'function' and C++ object destruction is
       #        non-portable
       # This warning is unavoidable when using e.g. setjmp/longjmp.  MSDN
       # suggests using exceptions instead of setjmp/longjmp for C++, but
       # Chromium code compiles without exception support.  We therefore have to
       # use setjmp/longjmp for e.g. JPEG decode error handling, which means we
       # have to turn off this warning (and be careful about how object
       # destruction happens in such cases).
       "/wd4611",
-
       # Warnings to evaluate and possibly fix/reenable later:
 
       "/wd4100",  # Unreferenced formal function parameter.
       "/wd4121",  # Alignment of a member was sensitive to packing.
       "/wd4244",  # Conversion: possible loss of data.
       "/wd4481",  # Nonstandard extension: override specifier.
       "/wd4505",  # Unreferenced local function has been removed.
       "/wd4510",  # Default constructor could not be generated.
       "/wd4512",  # Assignment operator could not be generated.
       "/wd4610",  # Class can never be instantiated, constructor required.
@@ skipping 313 matching lines @@
       cflags += [ "-gsplit-dwarf" ]
     }
   }
 }
 
 config("no_symbols") {
   if (!is_win) {
     cflags = [ "-g0" ]
   }
 }