[Android] Sets up a coverage system for java using EMMA

build/common.gypi

 # Copyright (c) 2012 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.
 
 # IMPORTANT:
 # Please don't directly include this file if you are building via gyp_chromium,
 # since gyp_chromium is automatically forcing its inclusion.
 {
   # Variables expected to be overriden on the GYP command line (-D) or by
   # ~/.gyp/include.gypi.
@@ skipping 886 matching lines @@
     # share the same compiler executable as the system driving the compilation,
     # because precompiled headers rely on pointers into a specific compiler
     # executable's image.  Setting this to 0 is needed to use an experimental
     # Linux-Mac cross compiler distcc farm.
     'chromium_mac_pch%': 1,
 
     # The default value for mac_strip in target_defaults. This cannot be
     # set there, per the comment about variable% in a target_defaults.
     'mac_strip_release%': 1,
 
-    # Set to 1 to enable code coverage.  In addition to build changes
+    # Set to 1 to enable native code coverage.  In addition to build changes
     # (e.g. extra CFLAGS), also creates a new target in the src/chrome
     # project file called "coverage".
     # Currently ignored on Windows.
     'coverage%': 0,
 
+    # Set to 1 to enable java code coverage. Instruments classes during build
+    # to produce .ec files during runtime.
+    'emma_coverage%': 0,
+
     # Set to 1 to force Visual C++ to use legacy debug information format /Z7.
     # This is useful for parallel compilation tools which can't support /Zi.
     # Only used on Windows.
     'win_z7%' : 0,
 
     # Although base/allocator lets you select a heap library via an
     # environment variable, the libcmt shim it uses sometimes gets in
     # the way.  To disable it entirely, and switch to normal msvcrt, do e.g.
     #  'win_use_allocator_shim': 0,
     #  'win_release_RuntimeLibrary': 2
@@ skipping 3786 matching lines @@
     # settings in target dicts.  SYMROOT is a special case, because many other
     # Xcode variables depend on it, including variables such as
     # PROJECT_DERIVED_FILE_DIR.  When a source group corresponding to something
     # like PROJECT_DERIVED_FILE_DIR is added to a project, in order for the
     # files to appear (when present) in the UI as actual files and not red
     # red "missing file" proxies, the correct path to PROJECT_DERIVED_FILE_DIR,
     # and therefore SYMROOT, needs to be set at the project level.
     'SYMROOT': '<(DEPTH)/xcodebuild',
   },
 }