Create Cronet extension in v2

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=131393395

extensions/cronet/README.md

+# ExoPlayer Cronet Extension #
+
+## Description ##
+
+[Cronet][] is Chromium's Networking stack packaged as a library.
+
+The Cronet Extension is an [HttpDataSource][] implementation using [Cronet][].
+
+[HttpDataSource]: https://google.github.io/ExoPlayer/doc/reference/com/google/android/exoplayer/upstream/HttpDataSource.html
+[Cronet]: https://chromium.googlesource.com/chromium/src/+/master/components/cronet?autodive=0%2F%2F
+
+## Build Instructions ##
+
+* Checkout ExoPlayer along with Extensions:
+
+```
+git clone https://github.com/google/ExoPlayer.git
+```
+
+* Get the Cronet libraries:
+
+1. Find the latest Cronet release [here][] and navigate to its `Release/cronet`
+   directory
+1. Download `cronet.jar`, `cronet_api.jar` and the `libs` directory
+1. Copy the two jar files into the `libs` directory of this extension
+1. Copy the content of the downloaded `libs` directory into the `jniLibs`
+   directory of this extension
+
+* In ExoPlayer's `settings.gradle` file, uncomment the Cronet extension
+
+[here]: https://console.cloud.google.com/storage/browser/chromium-cronet/android

extensions/cronet/build.gradle

+// Copyright (C) 2014 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+apply plugin: 'com.android.library'
+
+android {
+    compileSdkVersion 23
+    buildToolsVersion "23.0.1"
+
+    defaultConfig {
+        minSdkVersion 9
+        targetSdkVersion 23
+        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
+    }
+
+    buildTypes {
+        release {
+            minifyEnabled false
+            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt'
+        }
+    }
+
+    lintOptions {
+        abortOnError false
+    }
+
+    sourceSets.main {
+        jniLibs.srcDirs = ['jniLibs']
+    }
+}
+
+dependencies {
+    compile project(':library')
+    compile files('libs/cronet_api.jar')
+    compile files('libs/cronet.jar')
+    androidTestCompile 'com.google.dexmaker:dexmaker:1.2'
+    androidTestCompile 'com.google.dexmaker:dexmaker-mockito:1.2'
+    androidTestCompile 'org.mockito:mockito-core:1.9.5'
+    androidTestCompile project(':library')
+    androidTestCompile 'com.android.support.test:runner:0.4'
+}

extensions/cronet/jniLibs/README.md

+Copy folders containing architecture specific .so files here.

extensions/cronet/libs/README.md

+Copy cronet.jar and cronet_api.jar here.

library/src/main/java/com/google/android/exoplayer2/util/Clock.java

+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2.util;
+
+/**
+ * An interface through which system clocks can be read. The {@link SystemClock} implementation
+ * must be used for all non-test cases.
+ */
+public interface Clock {
+
+  /**
+   * Returns {@link android.os.SystemClock#elapsedRealtime}.
+   *
+   * @return Elapsed milliseconds since boot.
+   */
+  long elapsedRealtime();
+
+}

library/src/main/java/com/google/android/exoplayer2/util/SystemClock.java

+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2.util;
+
+/**
+ * The standard implementation of {@link Clock}.
+ */
+public final class SystemClock implements Clock {
+
+  @Override
+  public long elapsedRealtime() {
+    return android.os.SystemClock.elapsedRealtime();
+  }
+
+}

settings.gradle

@@ -20,10 +20,15 @@ include ':extension-vp9'
 include ':extension-okhttp'
 include ':extension-flac'
 include ':extension-ffmpeg'
+// Uncomment the following line to use the Cronet Extension.
+// include ':extension-cronet'
+
 
 project(':extension-opus').projectDir = new File(settingsDir, 'extensions/opus')
 project(':extension-vp9').projectDir = new File(settingsDir, 'extensions/vp9')
 project(':extension-okhttp').projectDir = new File(settingsDir, 'extensions/okhttp')
 project(':extension-flac').projectDir = new File(settingsDir, 'extensions/flac')
 project(':extension-ffmpeg').projectDir = new File(settingsDir, 'extensions/ffmpeg')
-
+// Uncomment the following line to use the Cronet Extension.
+// See extensions/cronet/README.md for details.
+// project(':extension-cronet').projectDir = new File(settingsDir, 'extensions/cronet')