De-duplicate BASE_IMPLEMENTATION define in the GN build.

TBR=ncbray

Review URL: https://codereview.chromium.org/1016443002

Cr-Commit-Position: refs/heads/master@{#320771}

base/BUILD.gn

@@ -9,6 +9,10 @@ if (is_android) {
   import("//build/config/android/rules.gni")
 }
 
+config("base_implementation") {
+  defines = [ "BASE_IMPLEMENTATION" ]
+}
+
 source_set("base_paths") {
   sources = [
     "base_paths.cc",
@@ -34,7 +38,7 @@ source_set("base_paths") {
     ]
   }
 
-  defines = [ "BASE_IMPLEMENTATION" ]
+  configs += [ ":base_implementation" ]
 
   deps = [
     "//base/memory",
@@ -607,7 +611,7 @@ component("base") {
     "sys_info_openbsd.cc",
   ]
 
-  defines = [ "BASE_IMPLEMENTATION" ]
+  configs += [ ":base_implementation" ]
 
   deps = [
     ":base_static",
@@ -630,7 +634,7 @@ component("base") {
   # Allow more direct string conversions on platforms with native utf8
   # strings
   if (is_mac || is_ios || is_chromeos) {
-    defines += [ "SYSTEM_NATIVE_UTF8" ]
+    defines = [ "SYSTEM_NATIVE_UTF8" ]
   }
 
   if (is_android) {
@@ -1279,8 +1283,6 @@ test("base_unittests") {
     "win/wrapped_window_proc_unittest.cc",
   ]
 
-  defines = []
-
   deps = [
     ":base",
     ":i18n",
@@ -1300,7 +1302,7 @@ test("base_unittests") {
   # Allow more direct string conversions on platforms with native utf8
   # strings
   if (is_mac || is_ios || is_chromeos) {
-    defines += [ "SYSTEM_NATIVE_UTF8" ]
+    defines = [ "SYSTEM_NATIVE_UTF8" ]
   }
 
   if (is_android) {

base/debug/BUILD.gn

@@ -55,7 +55,7 @@ source_set("debug") {
     ]
   }
 
-  defines = [ "BASE_IMPLEMENTATION" ]
+  configs += [ "//base:base_implementation" ]
 
   deps = [
     "//base/memory",
@@ -63,7 +63,7 @@ source_set("debug") {
   ]
 
   if (is_linux) {
-    defines += [ "USE_SYMBOLIZE" ]
+    defines = [ "USE_SYMBOLIZE" ]
     deps += [ "//base/third_party/symbolize" ]
   }
 

base/json/BUILD.gn

@@ -27,7 +27,7 @@ source_set("json") {
     ]
   }
 
-  defines = [ "BASE_IMPLEMENTATION" ]
+  configs += [ "//base:base_implementation" ]
 
   deps = [
     "//base/memory",

base/memory/BUILD.gn

@@ -54,7 +54,7 @@ source_set("memory") {
     sources -= [ "shared_memory_nacl.cc" ]
   }
 
-  defines = [ "BASE_IMPLEMENTATION" ]
+  configs += [ "//base:base_implementation" ]
 
   visibility = [ "//base/*" ]
 }

base/metrics/BUILD.gn

@@ -37,7 +37,7 @@ source_set("metrics") {
     sources -= [ "field_trial.cc" ]
   }
 
-  defines = [ "BASE_IMPLEMENTATION" ]
+  configs += [ "//base:base_implementation" ]
 
   deps = [
     "//base/debug",

base/process/BUILD.gn

@@ -94,7 +94,7 @@ source_set("process") {
     ]
   }
 
-  defines = [ "BASE_IMPLEMENTATION" ]
+  configs += [ "//base:base_implementation" ]
 
   deps = [
     "//base/memory",

base/third_party/nspr/BUILD.gn

@@ -12,7 +12,7 @@ source_set("nspr") {
 
   # In GYP this project is part of base, so it uses the base implementation
   # define. TODO(brettw) rename this define.
-  defines = [ "BASE_IMPLEMENTATION" ]
+  configs += [ "//base:base_implementation" ]
 
   if (is_android && !is_debug) {
     configs -= [ "//build/config/compiler:optimize" ]

base/trace_event/BUILD.gn

@@ -41,7 +41,7 @@ source_set("trace_event") {
     ]
   }
 
-  defines = [ "BASE_IMPLEMENTATION" ]
+  configs += [ "//base:base_implementation" ]
 
   deps = [
     "//base/debug",