Creating new gn arg: enable_all_proguard_optimizations.

build/config/android/config.gni

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # This file contains common system config stuff for the Android build.
 
 if (is_android) {
   assert(rebase_path("//", root_build_dir) == "../../",
          "Android output directory must be nested 2 levels within src/ (" +
              "e.g.: out-gn/Debug). http://crbug.com/412935")
@@ skipping 106 matching lines @@
 
     # EMMA filter string consisting of a list of inclusion/exclusion patterns
     # separated with whitespace and/or comma. Only has effect if
     # emma_coverage==true
     emma_filter = ""
 
     # Disables process isolation when building _incremental targets.
     # Required for Android M+ due to SELinux policies (stronger sandboxing).
     disable_incremental_isolated_processes = false
 
+    # Enables all ProGuard optimizations. These optimizations must not be
+    # enabled for instrumentation tests, since they cause code required by the
+    # tests to be removed.
+    # TODO(smaier): when buildbots get updated to set this flag, change the
+    # default to is_official_build
+    enable_all_proguard_optimizations = false
+
     # Speed up incremental compiles by compiling only changed files.
     enable_incremental_javac = false
 
     # Speed up dexing using dx --incremental.
     enable_incremental_dx = is_java_debug
 
-    # Neither of these should ever be used for release builds since they are
-    # somewhat experimental and dx --incremental is known to not produce
-    # byte-for-byte identical output.
-    assert(!(enable_incremental_dx && !is_java_debug))
-    assert(!(enable_incremental_javac && !is_java_debug))
-
     # Adds intrumentation to each function. Writes a file with the order that
     # functions are called at startup.
     use_order_profiling = false
   }
 
+  # Ensuring we never have a situation where we are asking to have debug java
+  # on alongside all ProGuard optimizations turned on, as these are mutually
+  # exclusive.
+  assert(!(is_java_debug && enable_all_proguard_optimizations))
+
+  # Neither of these should ever be used for release builds since they are
+  # somewhat experimental and dx --incremental is known to not produce
+  # byte-for-byte identical output.
+  assert(!(enable_incremental_dx && !is_java_debug))
+  assert(!(enable_incremental_javac && !is_java_debug))
+
   # Host stuff -----------------------------------------------------------------
 
   # Defines the name the Android build gives to the current host CPU
   # architecture, which is different than the names GN uses.
   if (host_cpu == "x64") {
     android_host_arch = "x86_64"
   } else if (host_cpu == "x86") {
     android_host_arch = "x86"
   } else {
     assert(false, "Need Android toolchain support for your build CPU arch.")
@@ skipping 128 matching lines @@
   } else if (current_cpu == "mips64el") {
     android_app_abi = "mips64"
   } else {
     assert(false, "Unknown Android ABI: " + current_cpu)
   }
 
   if (android_libcpp_lib_dir == "") {
     android_libcpp_lib_dir = "${android_libcpp_root}/libs/${android_app_abi}"
   }
 }