Port EMMA Java code coverage build rules to GN

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 51 matching lines @@
     # Set to true to run findbugs on JAR targets.
     run_findbugs = false
 
     # Set to true to enable verbose findbugs logging. This does nothing if
     # run_findbugs is false.
     findbugs_verbose = false
 
     # Set to true to enable the Errorprone compiler
     use_errorprone_java_compiler = false
 
+    # Enables EMMA Java code coverage. Instruments classes during build to
+    # produce .ec files during runtime
+    emma_coverage = false
+
+    # 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
 
     # Speed up incremental compiles by compiling only changed files.
     enable_incremental_javac = false
 
     # Speed up dexing using dx --incremental.
     enable_incremental_dx = is_debug
 
@@ skipping 143 matching lines @@
   } else if (current_cpu == "x64") {
     android_app_abi = "x86_64"
   } else if (current_cpu == "arm64") {
     android_app_abi = "arm64-v8a"
   } else if (current_cpu == "mips64el") {
     android_app_abi = "mips64"
   } else {
     assert(false, "Unknown Android ABI: " + current_cpu)
   }
 }