Address some TODO(GYP)s in the GN build.

build/config/compiler/BUILD.gn

Index: build/config/compiler/BUILD.gn
diff --git a/build/config/compiler/BUILD.gn b/build/config/compiler/BUILD.gn
index 229e394adb48a2aa86bdf768660390045763b1d9..a1b334d199be5d2f0698e5132992746ba12b2278 100644
--- a/build/config/compiler/BUILD.gn
+++ b/build/config/compiler/BUILD.gn
@@ -45,7 +45,7 @@ declare_args() {
   # Requires profiling to be set to true.
   enable_full_stack_frames_for_profiling = false
 
-  # TODO(GYP): We should be using 64-bit gold for linking on both 64-bit Linux
+  # TODO: We should be using 64-bit gold for linking on both 64-bit Linux
   # and 32-bit linux; 32-bit Gold runs out of address-space on 32-bit builds.
   # However, something isn't quite working right on the 32-bit builds.
   use_gold =
@@ -1335,9 +1335,6 @@ config("optimize_max") {
 
       # TODO(thakis): Remove is_clang here, https://crbug.com/598772
       if (is_official_build && !is_clang) {
-        # TODO(GYP): TODO(dpranke): Should these only be on in an official

[brettw, 2016/05/04 19:51:28]

I think we should do WPO only in official.

-        # build, or on all the time? For now we'll require official build so
-        # that the compile is clean.
         cflags += [
           "/GL",  # Whole program optimization.