clang/win: Take another stab at building with -Wunused-private-field.

BUG=505317
TBR=benwells@chromium.org

Review URL: https://codereview.chromium.org/1226373006 .

Cr-Commit-Position: refs/heads/master@{#338375}

build/common.gypi

@@ -5732,7 +5732,6 @@
                   '-Wno-switch',  # http://crbug.com/505308
                   '-Wno-unknown-pragmas',  # http://crbug.com/505314
                   '-Wno-unused-function',  # http://crbug.com/505316
-                  '-Wno-unused-private-field',  # http://crbug.com/505317
                   '-Wno-unused-value',  # http://crbug.com/505318
                   '-Wno-unused-variable',  # http://crbug.com/505319
                   '-Wno-unused-local-typedef',  # http://crbug.com/411648

build/config/compiler/BUILD.gn

@@ -805,7 +805,6 @@ if (is_win) {
       "-Wno-switch",  # http://crbug.com/505308
       "-Wno-unknown-pragmas",  # http://crbug.com/505314
       "-Wno-unused-function",  # http://crbug.com/505316
-      "-Wno-unused-private-field",  # http://crbug.com/505317
       "-Wno-unused-value",  # http://crbug.com/505318
       "-Wno-unused-variable",  # http://crbug.com/505319
       "-Wno-unused-local-typedef",  # http://crbug.com/411648

third_party/cld_2/BUILD.gn

@@ -83,7 +83,8 @@ source_set("cld2_platform_impl") {
 config("cld2_warnings") {
   if (is_clang) {
     cflags = [
-      # cld_2 has unused private fields.
+      # cld_2 contains unused private fields.
+      # https://code.google.com/p/cld2/issues/detail?id=37
       "-Wno-unused-private-field",
     ]
   }

third_party/cld_2/cld_2.gyp

@@ -178,7 +178,8 @@
         'clang_warning_flags': [
           # The generated files don't have braces around subobject initializers.
           '-Wno-missing-braces',
-          # cld_2 contains unused private fields.
+          # cld_2 contains unused private fields,
+          # https://code.google.com/p/cld2/issues/detail?id=37
           '-Wno-unused-private-field',
         ],
       },
@@ -203,6 +204,13 @@
         '<@(cld2_dynamic_data_loader_sources)',
       ],
       'defines': ['CLD2_DYNAMIC_MODE'],
+      'variables': {
+        'clang_warning_flags': [
+          # cld_2 contains unused private fields,
+          # https://code.google.com/p/cld2/issues/detail?id=37
+          '-Wno-unused-private-field',
+        ],
+      },
     },
   ],
 }

third_party/libphonenumber/BUILD.gn

@@ -51,6 +51,16 @@ static_library("libphonenumber_without_metadata") {
   configs -= [ "//build/config/compiler:chromium_code" ]
   configs += [ "//build/config/compiler:no_chromium_code" ]
 
+  config("libphonenumber_without_metadata_warnings") {
+    if (is_clang) {
+      cflags = [
+        # https://github.com/googlei18n/libphonenumber/pull/741
+        "-Wno-unused-private-field",
+      ]
+    }
+  }
+  configs += [ ":libphonenumber_without_metadata_warnings" ]
+
   public_configs = [ ":libphonenumber_config" ]
 
   public_deps = [

third_party/libphonenumber/libphonenumber.gyp

@@ -66,6 +66,10 @@
     'variables': {
       'proto_in_dir': 'src/resources',
       'proto_out_dir': 'third_party/libphonenumber/phonenumbers',
+      'clang_warning_flags': [
+        # https://github.com/googlei18n/libphonenumber/pull/741
+        '-Wno-unused-private-field',
+      ],
     },
     'includes': [ '../../build/protoc.gypi' ],
     'direct_dependent_settings': {