[Chromecast] Set symbol_level=2 for Chromecast builds by default.

build/config/compiler/compiler.gni

Index: build/config/compiler/compiler.gni
diff --git a/build/config/compiler/compiler.gni b/build/config/compiler/compiler.gni
index dc95f22eed7f1a1649a476493e049cd7a3017c9c..134f96ee9a21c96e78bbf4fffe0c5862d887df68 100644
--- a/build/config/compiler/compiler.gni
+++ b/build/config/compiler/compiler.gni
@@ -4,6 +4,7 @@
 
 import("//build/config/android/config.gni")
 import("//build/config/chrome_build.gni")
+import("//build/config/chromecast_build.gni")
 import("//build/config/sanitizers/sanitizers.gni")
 
 declare_args() {
@@ -27,10 +28,10 @@ if (symbol_level == -1) {
     # With instrumentation enabled, debug info puts libchrome.so over 4gb, which
     # causes the linker to produce an invalid ELF. http://crbug.com/574476
     symbol_level = 0
-  } else if (!is_linux || (is_debug || is_official_build)) {
+  } else if (!is_linux || is_debug || is_official_build || is_chromecast) {

[alokp, 2016/03/14 16:48:23]

This is OK, but can you explain what is wrong with setting this flag explicitly
in our makefile?

[slan, 2016/03/14 17:00:36]

This solution also ensures this behavior on Android and desktop Cast builds,
which the Makefile solution does not. Without this, we have to set this flag
explicitly to get stack traces on Eng and Release builds.

[alokp, 2016/03/14 17:13:53]

I am assuming that this only affects Eng builds, right? Because both Debug and
User builds should be handled by is_debug and is_official_build, respectively?
Not sure how important it is to set it for desktop release builds.

What is the issue with Android?

Note that I am not opposed to this patch, just trying to understand the need
before adding chromecast bits in a chromium-wide file.

     # Linux is slowed by having symbols as part of the target binary, whereas
     # Mac and Windows have them separate, so in Release Linux, default them off,
-    # but keep them on for Official builds.
+    # but keep them on for Official builds and Chromecast builds.
     symbol_level = 2
   } else if (using_sanitizer) {
     # Sanitizers require symbols for filename suppressions to work.