clang-format: Make continuation indent width configurable.

Patch by Kim Gräsman. Thank you!

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@192964 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/unittests/Format/FormatTest.cpp b/unittests/Format/FormatTest.cpp
index 5a8b5d6..1e898d8 100644
--- a/unittests/Format/FormatTest.cpp
+++ b/unittests/Format/FormatTest.cpp
@@ -6495,6 +6495,7 @@
   CHECK_PARSE("SpacesBeforeTrailingComments: 1234",
               SpacesBeforeTrailingComments, 1234u);
   CHECK_PARSE("IndentWidth: 32", IndentWidth, 32u);
+  CHECK_PARSE("ContinuationIndentWidth: 11", ContinuationIndentWidth, 11u);
 
   Style.Standard = FormatStyle::LS_Auto;
   CHECK_PARSE("Standard: Cpp03", Standard, FormatStyle::LS_Cpp03);
@@ -6876,5 +6877,23 @@
                "};");
 }
 
+TEST_F(FormatTest, ConfigurableContinuationIndentWidth) {
+  FormatStyle TwoIndent = getLLVMStyleWithColumns(15);
+  TwoIndent.ContinuationIndentWidth = 2;
+
+  EXPECT_EQ("int i =\n"
+            "  longFunction(\n"
+            "    arg);",
+            format("int i = longFunction(arg);", TwoIndent));
+
+  FormatStyle SixIndent = getLLVMStyleWithColumns(20);
+  SixIndent.ContinuationIndentWidth = 6;
+
+  EXPECT_EQ("int i =\n"
+            "      longFunction(\n"
+            "            arg);",
+            format("int i = longFunction(arg);", SixIndent));
+}
+
 } // end namespace tooling
 } // end namespace clang