Add GN conversions for more GYP flags

build/config/BUILDCONFIG.gn

Index: build/config/BUILDCONFIG.gn
diff --git a/build/config/BUILDCONFIG.gn b/build/config/BUILDCONFIG.gn
index 9e5f1094f7b59ba13401b186fd9438a0e4ae8655..afe24602f363bd614a333286962a2afb767aa088 100644
--- a/build/config/BUILDCONFIG.gn
+++ b/build/config/BUILDCONFIG.gn
@@ -65,6 +65,18 @@ declare_args() {
   # true means official Google Chrome branding (requires extra Google-internal
   # resources).
   is_chrome_branded = false
+
+  # Compile for Address Sanitizer to find memory bugs.
+  is_asan = false
+
+  # Compile for Leak Sanitizer to find leaks.
+  is_lsan = false
+
+  # Compile for Memory Sanitizer to find uninitialized reads.
+  is_msan = false
+
+  # Compile for Thread Sanitizer to find threading bugs.
+  is_tsan = false
 }
 
 # =============================================================================
@@ -280,6 +292,12 @@ if (is_component_build) {
   component_mode = "static_library"
 }
 
+# These Sanitizers all imply using the Clang compiler. On Windows they either
+# don't work or work differently.
+if (!is_clang && !is_win && (is_asan || is_lsan || is_tsan || is_msan)) {

[scottmg, 2013/12/20 22:03:37]

can you remove is_win (so that if the win-clang team wants to test things they
can use it?) or does syzyasan use is_asan too?

+  is_clang = true
+}
+
 toolkit_uses_gtk = is_linux
 
 # =============================================================================