Issue 5981 - Adjust build.gradle to support Kotlin

build.gradle

 buildscript {
-    ext.kotlin_version = '1.1.51'

[anton, 2017/11/03 12:00:20]

should not it be in the section below where the other versions are set?

[jens, 2017/11/03 12:45:54]

Yeah, I wonder why it's not. Looks like Android Studio moved it. I'll submit a
new patch set.

[diegocarloslima, 2017/11/08 11:37:20]

Minor thing, but for the other variables in ext, we specify them using camelCase
instead of underscore for word delimiters

+    // buildscript block is evaluated at the very beginning. Properties defined in the ext block
+    // don't exist at that time.
+    ext.kotlinVersion = '1.1.51'
     repositories {
         jcenter()
     }
     dependencies {
         classpath 'com.android.tools.build:gradle:2.3.1'
-        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlinVersion"
     }
 }
 
 allprojects {
     repositories {
         jcenter()
         mavenCentral()
     }
 }
 
 ext {
     minSdkVersion = 21
     targetSdkVersion = 25
     compileSdkVersion = 25
     buildToolsVersion = '25.0.3'
     androidSupportLibraryVersion = '25.3.1'
     sourceCompatibilityVersion = JavaVersion.VERSION_1_7
     targetCompatibilityVersion = JavaVersion.VERSION_1_7
     easyListUpdateUrl = 'https://easylist-downloads.adblockplus.org/easylist.txt'
     exceptionRulesUpdateUrl = 'https://easylist-downloads.adblockplus.org/exceptionrules.txt'
     easyListFilePath = file('adblockplussbrowser/res/raw/easylist.txt').absolutePath
     exceptionRulesFilePath = file('adblockplussbrowser/res/raw/exceptionrules.txt').absolutePath
 }