Add initial test and build files for Robolectric unit test suites.

Robolectric allows us to run tests that use Android code in the host
JVM. This means faster and more stable tests since we don't have to
deal with a device. This CL has the build file changes to build the
unit test suite, and two example tests that have been converted to
run with Robolectric.

BUG=448030

Review URL: https://codereview.chromium.org/994283006

Cr-Commit-Position: refs/heads/master@{#322512}

chrome/android/BUILD.gn

@@ -447,6 +447,19 @@ android_apk("chrome_shell_test_apk") {
   android_manifest = "shell/javatests/AndroidManifest.xml"
 }
 
+# GYP: //chrome/chrome_tests.gypi:chrome_shell_unit_tests
+java_binary("chrome_shell_unit_tests") {
+  testonly = true
+  java_files = [ "android/junit/src/org/chromium/chrome/browser/omaha/ResponseParserTest.java" ]
+  main_class = "org.chromium.testing.local.JunitTestMain"
+  deps = [
+    ":chrome_java",
+    "//base:base_java",
+    "//base:base_java_test_support",
+    "//testing/android/junit:junit_test_support",
+  ]
+}
+
 # GYP: //chrome/chrome_tests.gypi:chrome_sync_shell_test_apk
 android_apk("chrome_sync_shell_test_apk") {
   testonly = true

chrome/chrome_tests.gypi

@@ -2926,6 +2926,26 @@
           },
           'includes': [ '../build/java_apk.gypi' ],
         },
+        {
+          # GN: //chrome/android:chrome_shell_unit_tests
+          'target_name': 'chrome_shell_unit_tests',
+          'type': 'none',
+          'dependencies': [
+            'chrome_java',
+            '../base/base.gyp:base',
+            '../base/base.gyp:base_java_test_support',
+            '../testing/android/junit/junit_test.gyp:junit_test_support',
+          ],
+          'variables': {
+            'main_class': 'org.chromium.testing.local.JunitTestMain',
+            'src_paths': [
+              'android/junit/',
+            ],
+          },
+          'includes': [
+            '../build/host_jar.gypi',
+          ],
+        },
         {
           # GN: //chrome/test/chromedriver/test/webview_shell:chromedriver_webview_shell_apk
           'target_name': 'chromedriver_webview_shell_apk',

content/content_tests.gypi

@@ -2026,6 +2026,26 @@
           },
           'includes': [ '../build/java_apk.gypi' ],
         },
+        {
+          # GN: //content/public/android:content_shell_unit_tests
+          'target_name': 'content_shell_unit_tests',
+          'type': 'none',
+          'dependencies': [
+            'content.gyp:content_java',
+            '../base/base.gyp:base_java',
+            '../base/base.gyp:base_java_test_support',
+            '../testing/android/junit/junit_test.gyp:junit_test_support',
+          ],
+          'variables': {
+            'main_class': 'org.chromium.testing.local.JunitTestMain',
+            'src_paths': [
+              'public/android/junit/',
+            ],
+          },
+          'includes': [
+            '../build/host_jar.gypi',
+          ],
+        },
       ],
     }],
     ['OS!="android" and OS!="ios" and OS!="linux"', {

content/public/android/BUILD.gn

@@ -178,4 +178,17 @@ android_library("content_javatests") {
 
   DEPRECATED_java_in_dir = "javatests/src"
 }
+
+# GYP: //content/content_tests.gypi:content_shell_unit_tests
+java_binary("chrome_shell_unit_tests") {
+  testonly = true
+  java_files = [ "junit/src/org/chromium/content/browser/input/GamepadMappingsTest.java" ]
+  main_class = "org.chromium.testing.local.JunitTestMain"
+  deps = [
+    ":content_java",
+    "//base:base_java",
+    "//base:base_java_test_support",
+    "//testing/android/junit:junit_test_support",
+  ]
+}
 # TODO(GYP): content_icudata