Default runner to junit4

Bug: chromium:868610
Change-Id: Ifc457d8e74cf42e9ba4d21807721f86c521b35e9
Reviewed-on: https://webrtc-review.googlesource.com/94440
Reviewed-by: Sami Kalliomäki <sakal@webrtc.org>
Reviewed-by: Patrik Höglund <phoglund@webrtc.org>
Commit-Queue: Andrew Luo <aluo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#24350}
diff --git a/examples/androidtests/AndroidManifest.xml b/examples/androidtests/AndroidManifest.xml
index 7ce02dc..7cd52bc 100644
--- a/examples/androidtests/AndroidManifest.xml
+++ b/examples/androidtests/AndroidManifest.xml
@@ -20,11 +20,8 @@
         <uses-library android:name="android.test.runner" />
     </application>
 
-    <!-- tools:ignore needed for chromium-junit4 tag. crbug.com/640116
-         TODO(sakal): Remove once the tag is no longer needed. -->
     <instrumentation android:name="android.support.test.runner.AndroidJUnitRunner"
         tools:ignore="MissingPrefix"
         android:targetPackage="org.appspot.apprtc"
-        android:label="Tests for AppRTCMobile"
-        chromium-junit4="true"/>
+        android:label="Tests for AppRTCMobile"/>
 </manifest>
diff --git a/sdk/android/instrumentationtests/AndroidManifest.xml b/sdk/android/instrumentationtests/AndroidManifest.xml
index 591932c..75df968 100644
--- a/sdk/android/instrumentationtests/AndroidManifest.xml
+++ b/sdk/android/instrumentationtests/AndroidManifest.xml
@@ -31,11 +31,8 @@
         <uses-library android:name="android.test.runner" />
     </application>
 
-    <!-- tools:ignore needed for chromium-junit4 tag. crbug.com/640116
-         TODO(sakal): Remove once the tag is no longer needed. -->
     <instrumentation android:name="org.chromium.base.test.BaseChromiumAndroidJUnitRunner"
         tools:ignore="MissingPrefix"
         android:targetPackage="org.webrtc"
-        android:label="Tests for WebRTC Android SDK"
-        chromium-junit4="true"/>
+        android:label="Tests for WebRTC Android SDK"/>
 </manifest>
diff --git a/test/android/AndroidManifest.xml b/test/android/AndroidManifest.xml
index f8eb2e5..c1ddfd4 100644
--- a/test/android/AndroidManifest.xml
+++ b/test/android/AndroidManifest.xml
@@ -41,6 +41,7 @@
 
     <instrumentation android:name="org.chromium.native_test.NativeTestInstrumentationTestRunner"
             android:targetPackage="org.webrtc.native_test"
-            android:label="Instrumentation entry point for org.webrtc.native_test"/>
+            android:label="Instrumentation entry point for org.webrtc.native_test"
+            chromium-junit3="true"/>
 
 </manifest>