Add tv module for USB tuner support + demo app

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=168366847

.gitignore

@@ -39,6 +39,7 @@ proguard-project.txt
 
 # Other
 .DS_Store
+cmake-build-debug
 dist
 tmp
 

demos/tv/README.md

+# TV tuner demo application #
+
+This folder contains a demo application that uses ExoPlayer to play broadcast
+TV from USB tuners.

demos/tv/build.gradle

+// Copyright (C) 2017 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 from: '../../constants.gradle'
+apply plugin: 'com.android.application'
+
+android {
+    compileSdkVersion project.ext.compileSdkVersion
+    buildToolsVersion project.ext.buildToolsVersion
+
+    defaultConfig {
+        minSdkVersion 21
+        targetSdkVersion project.ext.targetSdkVersion
+    }
+
+    buildTypes {
+        release {
+            shrinkResources true
+            minifyEnabled true
+            proguardFiles getDefaultProguardFile('proguard-android.txt')
+        }
+        debug {
+            jniDebuggable = true
+        }
+    }
+
+    lintOptions {
+        // The demo app does not have translations.
+        disable 'MissingTranslation'
+    }
+
+}
+
+dependencies {
+    compile project(modulePrefix + 'library-core')
+    compile project(modulePrefix + 'library-ui')
+    compile project(modulePrefix + 'internal-extension-tv')
+    compile project(modulePrefix + 'extension-ffmpeg')
+}

extensions/tv/README.md

+# ExoPlayer TV tuner extension #
+
+Provides components for broadcast TV playback with ExoPlayer.
+
+## Links ##
+
+* [Javadoc][]: Classes matching `com.google.android.exoplayer2.ext.tv.*`
+  belong to this extension.
+
+[Javadoc]: https://google.github.io/ExoPlayer/doc/reference/index.html
+
+## Build Instructions ##
+
+* Checkout ExoPlayer:
+
+```
+git clone https://github.com/google/ExoPlayer.git
+```
+
+* Set the following environment variables:
+
+```
+cd "<path to exoplayer checkout>"
+EXOPLAYER_ROOT="$(pwd)"
+TV_MODULE_PATH="${EXOPLAYER_ROOT}/extensions/tv/src/main"
+```
+
+* Download the [Android NDK][] and set its location in an environment variable:
+
+[Android NDK]: https://developer.android.com/tools/sdk/ndk/index.html
+
+```
+NDK_PATH="<path to Android NDK>"
+```
+
+* Build the JNI native libraries from the command line:
+
+```
+cd "${TV_MODULE_PATH}"/jni && \
+${NDK_PATH}/ndk-build APP_ABI=all -j<N>
+```

extensions/tv/build.gradle

+// Copyright (C) 2017 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 from: '../../constants.gradle'
+apply plugin: 'com.android.library'
+
+android {
+    compileSdkVersion project.ext.compileSdkVersion
+    buildToolsVersion project.ext.buildToolsVersion
+
+    defaultConfig {
+        minSdkVersion 21
+        targetSdkVersion project.ext.targetSdkVersion
+    }
+
+    sourceSets.main {
+        jniLibs.srcDir 'src/main/libs'
+        jni.srcDirs = [] // Disable the automatic ndk-build call by Android Studio.
+    }
+}
+
+dependencies {
+    compile project(modulePrefix + 'library-core')
+}
+
+ext {
+    javadocTitle = 'TV tuner extension'
+}
+apply from: '../../javadoc_library.gradle'

library/core/src/main/java/com/google/android/exoplayer2/util/ParsableBitArray.java

@@ -63,6 +63,17 @@ public final class ParsableBitArray {
   }
 
   /**
+   * Sets this instance's data, position and limit to match the provided {@code parsableByteArray}.
+   * Any modifications to the underlying data array will be visible in both instances
+   *
+   * @param parsableByteArray The {@link ParsableByteArray}.
+   */
+  public void reset(ParsableByteArray parsableByteArray) {
+    reset(parsableByteArray.data, parsableByteArray.limit());
+    setPosition(parsableByteArray.getPosition() * 8);
+  }
+
+  /**
    * Updates the instance to wrap {@code data}, and resets the position to zero.
    *
    * @param data The array to wrap.