Disable compilation symbols on goma builds

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 91f40810a826672c7062fc11c551e267711e51c6..79c79a42d21ad8fdb6f807ab5ae6990280b20693 100644
--- a/build/config/compiler/BUILD.gn
+++ b/build/config/compiler/BUILD.gn
@@ -1487,7 +1487,10 @@ config("symbols") {
   if (is_win) {
     import("//build/toolchain/goma.gni")
     if (use_goma) {
-      cflags = [ "/Z7" ]  # No PDB file
+      # Disable symbols during goma compilation because otherwise the redundant
+      # debug information (repeated in every .obj file) makes linker memory
+      # consumption and link times unsustainable (crbug.com/630074).
+      cflags = []

[Dirk Pranke, 2016/07/22 21:02:56]

The implication of this change is that you can no longer get a full symbol build
w/ goma, right? 

Maybe it would've been better to change it so that if use_goma=true,
symbol_level defaults to 1 ?

That would also make things more consistent w/ what we do on the builders, which
would be nice.

It also looks like we might need /z7 for SyzygyASAN (we'll have to check w/
Sébastien).

     } else {
       cflags = [ "/Zi" ]  # Produce PDB file, no edit and continue.
     }