Use protobuf with renamed packages, pack to IDEA plugin

Update GenerateProtoBuf.kt to also regexp-replace com.google.protobuf with
org.jetbrains.kotlin.protobuf in generated Java sources

 #KT-12581 Fixed

generators/src/org/jetbrains/kotlin/generators/protobuf/GenerateProtoBuf.kt

@@ -18,6 +18,7 @@ package org.jetbrains.kotlin.generators.protobuf
 
 import com.intellij.execution.configurations.GeneralCommandLine
 import com.intellij.execution.util.ExecUtil
+import com.intellij.util.LineSeparator
 import java.io.File
 import java.util.regex.Pattern
 
@@ -104,6 +105,32 @@ private fun execProtoc(protoPath: String, outPath: String) {
     if (processOutput.stderr.isNotEmpty()) {
         throw AssertionError(processOutput.stderr)
     }
+
+    renamePackages(protoPath, outPath)
+}
+
+private fun renamePackages(protoPath: String, outPath: String) {
+    fun List<String>.findValue(regex: Regex): String? =
+            mapNotNull { line ->
+                regex.find(line)?.groupValues?.get(1)
+            }.singleOrNull()
+
+    val protoFileContents = File(protoPath).readLines()
+    val packageName = protoFileContents.findValue("package ([\\w.]+);".toRegex())
+                      ?: error("No package directive found in $protoPath")
+    val className = protoFileContents.findValue("option java_outer_classname = \"(\\w+)\";".toRegex())
+                    ?: error("No java_outer_classname option found in $protoPath")
+
+    val javaFile = File(outPath, "${packageName.replace('.', '/')}/$className.java")
+    if (!javaFile.exists()) {
+        throw AssertionError("File does not exist: $javaFile")
+    }
+
+    javaFile.writeText(
+            javaFile.readLines().map { line ->
+                line.replace("com.google.protobuf", "org.jetbrains.kotlin.protobuf")
+            }.joinToString(LineSeparator.getSystemLineSeparator().separatorString)
+    )
 }
 
 private fun modifyAndExecProtoc(protoPath: ProtoPath) {

generators/src/org/jetbrains/kotlin/generators/protobuf/GenerateProtoBufCompare.kt

@@ -16,8 +16,8 @@
 
 package org.jetbrains.kotlin.generators.protobuf
 
-import com.google.protobuf.Descriptors
 import org.jetbrains.kotlin.generators.util.GeneratorsFileUtil
+import org.jetbrains.kotlin.protobuf.Descriptors
 import org.jetbrains.kotlin.serialization.DebugExtOptionsProtoBuf
 import org.jetbrains.kotlin.serialization.DebugProtoBuf
 import org.jetbrains.kotlin.serialization.jvm.DebugJvmProtoBuf
@@ -39,7 +39,7 @@ class GenerateProtoBufCompare {
         }
     }
 
-    private val JAVA_TYPES_WITH_INLINED_EQUALS: EnumSet<com.google.protobuf.Descriptors.FieldDescriptor.JavaType> = EnumSet.of(
+    private val JAVA_TYPES_WITH_INLINED_EQUALS: EnumSet<Descriptors.FieldDescriptor.JavaType> = EnumSet.of(
             Descriptors.FieldDescriptor.JavaType.INT,
             Descriptors.FieldDescriptor.JavaType.LONG,
             Descriptors.FieldDescriptor.JavaType.FLOAT,

generators/tests/org/jetbrains/kotlin/generators/protobuf/ProtoBufConsistencyTest.kt

@@ -16,13 +16,12 @@
 
 package org.jetbrains.kotlin.generators.protobuf
 
-import junit.framework.TestCase
-import com.google.protobuf.GeneratedMessage.GeneratedExtension
-import java.lang.reflect.ParameterizedType
-import com.google.protobuf.Descriptors
-import kotlin.test.fail
 import com.google.common.collect.LinkedHashMultimap
+import junit.framework.TestCase
+import org.jetbrains.kotlin.protobuf.Descriptors
+import org.jetbrains.kotlin.protobuf.GeneratedMessage.GeneratedExtension
 import java.lang.reflect.Modifier
+import java.lang.reflect.ParameterizedType
 
 class ProtoBufConsistencyTest : TestCase() {
     fun testExtensionNumbersDoNotIntersect() {