Add OkHttp extension to V2.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=118775995

extensions/okhttp/README.md

+# ExoPlayer OkHttp Extension #
+
+## Description ##
+
+The OkHttp Extension is an [HttpDataSource][] implementation using Square's [OkHttp][].
+
+[HttpDataSource]: https://google.github.io/ExoPlayer/doc/reference/com/google/android/exoplayer/upstream/HttpDataSource.html
+[OkHttp]: https://square.github.io/okhttp/
+

extensions/okhttp/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
+    }
+
+    buildTypes {
+        release {
+            minifyEnabled false
+            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt'
+        }
+    }
+
+    lintOptions {
+        abortOnError false
+    }
+}
+
+dependencies {
+    compile project(':library')
+    compile('com.squareup.okhttp3:okhttp:+') {
+        exclude group: 'org.json'
+    }
+}

extensions/okhttp/src/main/.classpath

+<?xml version="1.0" encoding="UTF-8"?>
+<classpath>
+	<classpathentry exported="true" kind="con" path="com.android.ide.eclipse.adt.LIBRARIES"/>
+	<classpathentry kind="con" path="com.android.ide.eclipse.adt.ANDROID_FRAMEWORK"/>
+	<classpathentry exported="true" kind="con" path="com.android.ide.eclipse.adt.DEPENDENCIES"/>
+	<classpathentry combineaccessrules="false" exported="true" kind="src" path="/ExoPlayerLib"/>
+	<classpathentry kind="src" path="java"/>
+	<classpathentry kind="src" path="gen"/>
+	<classpathentry kind="output" path="bin/classes"/>
+</classpath>

extensions/okhttp/src/main/.project

+<?xml version="1.0" encoding="UTF-8"?>
+<projectDescription>
+	<name>ExoPlayerExt-OkHttp</name>
+	<comment></comment>
+	<projects>
+	</projects>
+	<buildSpec>
+		<buildCommand>
+			<name>com.android.ide.eclipse.adt.ResourceManagerBuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+		<buildCommand>
+			<name>com.android.ide.eclipse.adt.PreCompilerBuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+		<buildCommand>
+			<name>org.eclipse.jdt.core.javabuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+		<buildCommand>
+			<name>com.android.ide.eclipse.adt.ApkBuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+	</buildSpec>
+	<natures>
+		<nature>com.android.ide.eclipse.adt.AndroidNature</nature>
+		<nature>org.eclipse.jdt.core.javanature</nature>
+	</natures>
+</projectDescription>

extensions/okhttp/src/main/AndroidManifest.xml

+<?xml version="1.0" encoding="utf-8"?>
+<!-- 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.
+-->
+
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="com.google.android.exoplayer.ext.okhttp">
+
+    <uses-sdk android:minSdkVersion="9" android:targetSdkVersion="23"/>
+
+</manifest>

extensions/okhttp/src/main/project.properties

+# This file is automatically generated by Android Tools.
+# Do not modify this file -- YOUR CHANGES WILL BE ERASED!
+#
+# This file must be checked in Version Control Systems.
+#
+# To customize properties used by the Ant build system edit
+# "ant.properties", and override values to adapt the script to your
+# project structure.
+#
+# To enable ProGuard to shrink and obfuscate your code, uncomment this (available properties: sdk.dir, user.home):
+#proguard.config=${sdk.dir}/tools/proguard/proguard-android.txt:proguard-project.txt
+
+# Project target.
+target=android-23
+android.library=true
+android.library.reference.1=../../../../library/src/main