为什么play-services-location需要android.permission.WRITE_EXTERNAL_STORAGE和android.permission.READ_EXTERNAL_STORAGE权限？

<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>

将APK上传到开发者控制台后,它会添加两个新权限：

我的build.gradle：

apply plugin: 'com.android.application'

android {
    compileSdkVersion 22
    buildToolsVersion "22.0.1"

    defaultConfig {
        applicationId "net.perspiratron.ifpaprofile"
        minSdkVersion 15
        targetSdkVersion 22
        versionCode 3
        versionName "1.2"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'),'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs',include: ['*.jar'])
//    wearApp project(':wear')
    compile 'com.android.support:appcompat-v7:22.2.0'
    compile 'com.google.android.gms:play-services-analytics:7.5.0'
    compile 'com.google.android.gms:play-services-LOCATIOn:7.5.0'
    compile 'com.jjoe64:graphview:4.0.0'
}

我唯一添加的是播放服务位置.为什么这个图书馆需要它？