Index: include/clang/Format/Format.h
===================================================================
--- include/clang/Format/Format.h
+++ include/clang/Format/Format.h
@@ -390,6 +390,49 @@
   /// \endcode
   bool BinPackParameters;
 
+  /// \brief The style of wrapping parameters on the same line (bin-packed) or
+  /// on one line each.
+  enum BinPackStyle {
+    /// Automatically determine parameter bin-packing behavior.
+    BPS_Auto,
+    /// Always bin-pack parameters.
+    BPS_Always,
+    /// Never bin-pack parameters.
+    BPS_Never,
+  };
+
+  /// \brief Controls bin-packing Objective-C protocol conformance list
+  /// items into as few lines as possible when they go over `ColumnLimit`.
+  ///
+  /// If ``Auto`` (the default), delegates to the value in
+  /// ``BinPackParameters``. If that is ``true``, bin-packs Objective-C
+  /// protocol conformance list items into as few lines as possible
+  /// whenever they go over ``ColumnLimit``.
+  ///
+  /// If ``Always``, always bin-packs Objective-C protocol conformance
+  /// list items into as few lines as possible whenever they go over
+  /// ``ColumnLimit``.
+  ///
+  /// If ``Never``, lays out Objective-C protocol conformance list items
+  /// onto individual lines whenever they go over ``ColumnLimit``.
+  ///
+  /// \code
+  ///    Always (or Auto, if BinPackParameters=true):
+  ///    @interface ccccccccccccc () <
+  ///        ccccccccccccc, ccccccccccccc,
+  ///        ccccccccccccc, ccccccccccccc> {
+  ///    }
+  ///
+  ///    Never (or Auto, if BinPackParameters=false):
+  ///    @interface ddddddddddddd () <
+  ///        ddddddddddddd,
+  ///        ddddddddddddd,
+  ///        ddddddddddddd,
+  ///        ddddddddddddd> {
+  ///    }
+  /// \endcode
+  BinPackStyle BinPackObjCProtocolList;
+
   /// \brief The style of breaking before or after binary operators.
   enum BinaryOperatorStyle {
     /// Break after operators.
@@ -1646,6 +1689,7 @@
                R.AlwaysBreakTemplateDeclarations &&
            BinPackArguments == R.BinPackArguments &&
            BinPackParameters == R.BinPackParameters &&
+           BinPackObjCProtocolList == R.BinPackObjCProtocolList &&
            BreakBeforeBinaryOperators == R.BreakBeforeBinaryOperators &&
            BreakBeforeBraces == R.BreakBeforeBraces &&
            BreakBeforeTernaryOperators == R.BreakBeforeTernaryOperators &&
Index: lib/Format/ContinuationIndenter.cpp
===================================================================
--- lib/Format/ContinuationIndenter.cpp
+++ lib/Format/ContinuationIndenter.cpp
@@ -1222,9 +1222,20 @@
         Current.MatchingParen->getPreviousNonComment() &&
         Current.MatchingParen->getPreviousNonComment()->is(tok::comma);
 
+    // If BinPackObjCProtocolList is unspecified, fall back to BinPackParameters
+    // for backwards compatibility.
+    bool BinPackObjCProtocolList =
+        (Style.BinPackObjCProtocolList == FormatStyle::BPS_Auto &&
+         Style.BinPackParameters) ||
+        Style.BinPackObjCProtocolList == FormatStyle::BPS_Always;
+
+    bool BinPackDeclaration =
+        (State.Line->Type != LT_ObjCDecl && Style.BinPackParameters) ||
+        (State.Line->Type == LT_ObjCDecl && BinPackObjCProtocolList);
+
     AvoidBinPacking =
         (Style.Language == FormatStyle::LK_JavaScript && EndsInComma) ||
-        (State.Line->MustBeDeclaration && !Style.BinPackParameters) ||
+        (State.Line->MustBeDeclaration && !BinPackDeclaration) ||
         (!State.Line->MustBeDeclaration && !Style.BinPackArguments) ||
         (Style.ExperimentalAutoDetectBinPacking &&
          (Current.PackingKind == PPK_OnePerLine ||
Index: lib/Format/Format.cpp
===================================================================
--- lib/Format/Format.cpp
+++ lib/Format/Format.cpp
@@ -105,6 +105,14 @@
   }
 };
 
+template <> struct ScalarEnumerationTraits<FormatStyle::BinPackStyle> {
+  static void enumeration(IO &IO, FormatStyle::BinPackStyle &Value) {
+    IO.enumCase(Value, "Auto", FormatStyle::BPS_Auto);
+    IO.enumCase(Value, "Always", FormatStyle::BPS_Always);
+    IO.enumCase(Value, "Never", FormatStyle::BPS_Never);
+  }
+};
+
 template <> struct ScalarEnumerationTraits<FormatStyle::BinaryOperatorStyle> {
   static void enumeration(IO &IO, FormatStyle::BinaryOperatorStyle &Value) {
     IO.enumCase(Value, "All", FormatStyle::BOS_All);
@@ -323,6 +331,7 @@
                    Style.AlwaysBreakTemplateDeclarations);
     IO.mapOptional("BinPackArguments", Style.BinPackArguments);
     IO.mapOptional("BinPackParameters", Style.BinPackParameters);
+    IO.mapOptional("BinPackObjCProtocolList", Style.BinPackObjCProtocolList);
     IO.mapOptional("BraceWrapping", Style.BraceWrapping);
     IO.mapOptional("BreakBeforeBinaryOperators",
                    Style.BreakBeforeBinaryOperators);
@@ -599,6 +608,7 @@
   LLVMStyle.AlwaysBreakTemplateDeclarations = false;
   LLVMStyle.BinPackArguments = true;
   LLVMStyle.BinPackParameters = true;
+  LLVMStyle.BinPackObjCProtocolList = FormatStyle::BPS_Auto;
   LLVMStyle.BreakBeforeBinaryOperators = FormatStyle::BOS_None;
   LLVMStyle.BreakBeforeTernaryOperators = true;
   LLVMStyle.BreakBeforeBraces = FormatStyle::BS_Attach;
Index: unittests/Format/FormatTestObjC.cpp
===================================================================
--- unittests/Format/FormatTestObjC.cpp
+++ unittests/Format/FormatTestObjC.cpp
@@ -281,8 +281,7 @@
                "    ccccccccccccc, ccccccccccccc,\n"
                "    ccccccccccccc, ccccccccccccc> {\n"
                "}");
-
-  Style.BinPackParameters = false;
+  Style.BinPackObjCProtocolList = FormatStyle::BPS_Never;
   verifyFormat("@interface ddddddddddddd () <\n"
                "    ddddddddddddd,\n"
                "    ddddddddddddd,\n"
@@ -290,6 +289,20 @@
                "    ddddddddddddd> {\n"
                "}");
 
+  Style.BinPackParameters = false;
+  Style.BinPackObjCProtocolList = FormatStyle::BPS_Auto;
+  verifyFormat("@interface eeeeeeeeeeeee () <\n"
+               "    eeeeeeeeeeeee,\n"
+               "    eeeeeeeeeeeee,\n"
+               "    eeeeeeeeeeeee,\n"
+               "    eeeeeeeeeeeee> {\n"
+               "}");
+  Style.BinPackObjCProtocolList = FormatStyle::BPS_Always;
+  verifyFormat("@interface fffffffffffff () <\n"
+               "    fffffffffffff, fffffffffffff,\n"
+               "    fffffffffffff, fffffffffffff> {\n"
+               "}");
+
   Style = getGoogleStyle(FormatStyle::LK_ObjC);
   verifyFormat("@interface Foo : NSObject <NSSomeDelegate> {\n"
                " @public\n"