GN: fixes for the official build.

The C++ define OFFICIAL_BUILD wasn't getting set, and the widevine version .rc files was getting linked twice.

CQ_EXTRA_TRYBOTS=tryserver.chromium.linux:android_chromium_gn_compile_dbg,android_chromium_gn_compile_rel;tryserver.chromium.win:win8_chromium_gn_rel,win8_chromium_gn_dbg;tryserver.chromium.mac:mac_chromium_gn_rel,mac_chromium_gn_dbg

R=dpranke
TBR=ddorwin@chromium.org

Review URL: https://codereview.chromium.org/1134623003

Cr-Commit-Position: refs/heads/master@{#329308}

build/config/BUILD.gn

@@ -41,9 +41,8 @@ declare_args() {
 #
 # For now we define these globally to match the current GYP build.
 config("feature_flags") {
-  # TODO(brettw) most of these need to be parameterized.
+  # TODO(brettw) this probably needs to be parameterized.
   defines = [
-    "CHROMIUM_BUILD",
     "V8_DEPRECATION_WARNINGS",  # Don't use deprecated V8 APIs anywhere.
   ]
 
@@ -239,6 +238,14 @@ config("feature_flags") {
     defines += [ "MOBILE_SAFE_BROWSING" ]
     defines += [ "SAFE_BROWSING_SERVICE" ]
   }
+  if (is_official_build) {
+    defines += [ "OFFICIAL_BUILD" ]
+  }
+  if (is_chrome_branded) {
+    defines += [ "GOOGLE_CHROME_BUILD" ]
+  } else {
+    defines += [ "CHROMIUM_BUILD" ]
+  }
 }
 
 # Debug/release ----------------------------------------------------------------

third_party/widevine/cdm/BUILD.gn

@@ -110,22 +110,17 @@ if (widevine_cdm_binary_files != []) {
 }
 
 if ((is_chrome_branded || enable_widevine) && enable_pepper_cdms) {
-  adapter_resource_file = "$target_gen_dir/widevinecdmadapter_version.rc"
-
-  # Produce the .rc file.
+  # Produce and compile the .rc file.
   process_version("widevinecdmadapter_resources") {
     visibility = [ ":*" ]
     sources = [
       "BRANDING",
       "widevinecdmadapter.ver",
     ]
-    output = adapter_resource_file
+    output = "$target_gen_dir/widevinecdmadapter_version.rc"
   }
 
   cdm_adapter("widevinecdmadapter") {
-    sources = [
-      adapter_resource_file,
-    ]
     deps = [
       ":widevinecdmadapter_resources",
       ":widevinecdm",