Enable emma code coverage for JUnit testcases.

After setting emma_coverage as true, and then run JUnit testcases, code
coverage information will be stored in coverage.ec. In order to read
coverage.ec file, you will need to find the corresponding <name>.em file
in out-gn/Debug and then merge the .em and .ec file into a txt or html.

BUG=604900

Review URL: https://codereview.chromium.org/1913593002

Cr-Commit-Position: refs/heads/master@{#389902}

build/android/gyp/create_java_binary_script.py

@@ -37,6 +37,7 @@ if os.getcwd() != self_dir:
   classpath = [os.path.join(offset, p) for p in classpath]
   bootclasspath = [os.path.join(offset, p) for p in bootclasspath]
 java_cmd = ["java"]
+{noverify_flag}
 if bootclasspath:
     java_cmd.append("-Xbootclasspath/p:" + ":".join(bootclasspath))
 java_cmd.extend(
@@ -58,8 +59,16 @@ def main(argv):
       help='Classpath for running the jar.')
   parser.add_option('--bootclasspath', action='append', default=[],
       help='zip/jar files to add to bootclasspath for java cmd.')
+  parser.add_option('--noverify', action='store_true',
+      help='JVM flag: noverify.')
+
   options, extra_program_args = parser.parse_args(argv)
 
+  if (options.noverify):
+    noverify_flag = 'java_cmd.append("-noverify")'
+  else:
+    noverify_flag = ''
+
   classpath = [options.jar_path]
   for cp_arg in options.classpath:
     classpath += build_utils.ParseGypList(cp_arg)
@@ -78,7 +87,8 @@ def main(argv):
       bootclasspath=('"%s"' % '", "'.join(bootclasspath)
                      if bootclasspath else ''),
       main_class=options.main_class,
-      extra_program_args=repr(extra_program_args)))
+      extra_program_args=repr(extra_program_args),
+      noverify_flag=noverify_flag))
 
   os.chmod(options.output, 0750)
 

build/config/android/internal_rules.gni

@@ -240,6 +240,15 @@ template("java_binary_script") {
       "--main-class",
       _main_class,
     ]
+    if (emma_coverage) {
+      args += [
+        "--classpath",
+        rebase_path(
+            "//third_party/android_tools_internal/sdk/tools/lib/emma.jar",
+            root_build_dir),
+      ]
+      args += [ "--noverify" ]
+    }
     if (defined(invoker.wrapper_script_args)) {
       args += [ "--" ] + invoker.wrapper_script_args
     }