boost is downloaded from https://github.com/react-native-community/boost

Summary:
Improvement over #11469.
Depends on react-native-community/boost-for-react-native#1, **don't merge before it is fixed**.

It would be more in line with other dependencies  to depend only on github for thirdparty bridge dependencies.

**Test plan (required)**

- Circle (testing with caches cleaned)
- ./gradlew ReactAndroid:packageReactNdkLibsForBuck (check twice to make sure caches work)
REACT_NATIVE_BOOST_PATH=./path-to-local-boost/
- ./gradlew ReactAndroid:packageReactNdkLibsForBuck (check twice to make sure caches work)
Closes #11511

Differential Revision: D4348098

fbshipit-source-id: 5c2f25cc395ae0cad19d56b7c0b2b102513580fb

Author: bestander

ReactAndroid/build.gradle

@@ -35,33 +35,17 @@ task createNativeDepsDirectories {
 }
 
 task downloadBoost(dependsOn: createNativeDepsDirectories, type: Download) {
-    src 'https://registry.yarnpkg.com/boost-react-native-bundle/-/boost-react-native-bundle-1.57.0.tgz'
+    src 'https://github.com/react-native-community/boost-for-react-native/releases/download/v1.57.0-1/boost_1_57_0.tar.gz'
     onlyIfNewer true
     overwrite false
-    dest new File(downloadsDir, 'boost-react-native-bundle-1.57.0.tgz')
+    dest new File(downloadsDir, 'boost_1_57_0.tar.gz')
 }
 
-task unpackBoost(dependsOn: downloadBoost, type: Copy) {
-    from tarTree(resources.gzip(downloadBoost.dest))
-    include 'package/boost_1_57_0/boost/**/*.hpp'
-    into "$thirdPartyNdkDir/boost"
-    // npm packages are unpacked into folder "package" that we want to strip
-    eachFile { FileCopyDetails fcp ->
-        if (fcp.relativePath.pathString.startsWith("package")) {
-            // remap the file to the root
-            def segments = fcp.relativePath.segments
-            def pathsegments = segments[1..-1] as String[]
-            fcp.relativePath = new RelativePath(!fcp.file.isDirectory(), pathsegments)
-        } else {
-            fcp.exclude()
-        }
-    }
-}
-
-task prepareBoost(dependsOn: boostPath ? [] : [unpackBoost], type: Copy) {
-    from boostPath ?: []
+task prepareBoost(dependsOn: boostPath ? [] : [downloadBoost], type: Copy) {
+    from boostPath ?: tarTree(resources.gzip(downloadBoost.dest))
     from 'src/main/jni/third-party/boost/Android.mk'
     include 'boost_1_57_0/boost/**/*.hpp', 'Android.mk'
+    includeEmptyDirs = false
     into "$thirdPartyNdkDir/boost"
 }
 
@@ -135,7 +119,8 @@ task prepareGlog(dependsOn: dependenciesPath ? [] : [downloadGlog], type: Copy)
 }
 
 task downloadJSCHeaders(type: Download) {
-    def jscAPIBaseURL = 'https://svn.webkit.org/repository/webkit/!svn/bc/174650/trunk/Source/JavaScriptCore/API/'
+    // in sync with webkit SVN revision 174650
+    def jscAPIBaseURL = 'https://raw.githubusercontent.com/WebKit/webkit/38b15a3ba3c1b0798f2036f7cea36ffdc096202e/Source/JavaScriptCore/API/'
     def jscHeaderFiles = ['JavaScript.h', 'JSBase.h', 'JSContextRef.h', 'JSObjectRef.h', 'JSRetainPtr.h', 'JSStringRef.h', 'JSValueRef.h', 'WebKitAvailability.h']
     def output = new File(downloadsDir, 'jsc')
     output.mkdirs()