Index: lib/Format/ContinuationIndenter.cpp
===================================================================
--- lib/Format/ContinuationIndenter.cpp
+++ lib/Format/ContinuationIndenter.cpp
@@ -1988,7 +1988,7 @@
   if (Current.getNextNonComment() &&
       Current.getNextNonComment()->isStringLiteral())
     return true; // Implicit concatenation.
-  if (Style.ColumnLimit != 0 &&
+  if (Style.ColumnLimit != 0 && Style.BreakStringLiterals &&
       State.Column + Current.ColumnWidth + Current.UnbreakableTailLength >
           Style.ColumnLimit)
     return true; // String will be split.
Index: lib/Format/Format.cpp
===================================================================
--- lib/Format/Format.cpp
+++ lib/Format/Format.cpp
@@ -686,11 +686,6 @@
     FormatStyle GoogleStyle = getGoogleStyle(FormatStyle::LK_Proto);
     GoogleStyle.Language = FormatStyle::LK_TextProto;
 
-    // Text protos are currently mostly formatted inside C++ raw string literals
-    // and often the current breaking behavior of string literals is not
-    // beneficial there. Investigate turning this on once proper string reflow
-    // has been implemented.
-    GoogleStyle.BreakStringLiterals = false;
     return GoogleStyle;
   }
 
@@ -761,6 +756,11 @@
     GoogleStyle.AllowShortFunctionsOnASingleLine = FormatStyle::SFS_None;
     GoogleStyle.SpacesInContainerLiterals = false;
     GoogleStyle.Cpp11BracedListStyle = false;
+    // Text protos are currently mostly formatted inside C++ raw string literals
+    // and often the current breaking behavior of string literals is not
+    // beneficial there. Investigate turning this on once proper string reflow
+    // has been implemented.
+    GoogleStyle.BreakStringLiterals = false;
   } else if (Language == FormatStyle::LK_ObjC) {
     GoogleStyle.ColumnLimit = 100;
   }
Index: lib/Format/TokenAnnotator.cpp
===================================================================
--- lib/Format/TokenAnnotator.cpp
+++ lib/Format/TokenAnnotator.cpp
@@ -2820,11 +2820,17 @@
   if (Right.is(TT_ObjCMethodExpr) && !Right.is(tok::r_square) &&
       Left.isNot(TT_SelectorName))
     return true;
+
   if (Right.is(tok::colon) &&
       !Right.isOneOf(TT_CtorInitializerColon, TT_InlineASMColon))
     return false;
-  if (Left.is(tok::colon) && Left.isOneOf(TT_DictLiteral, TT_ObjCMethodExpr))
+  if (Left.is(tok::colon) && Left.isOneOf(TT_DictLiteral, TT_ObjCMethodExpr)) {
+    if ((Style.Language == FormatStyle::LK_Proto ||
+         Style.Language == FormatStyle::LK_TextProto) &&
+        Right.isStringLiteral())
+      return false;
     return true;
+  }
   if (Right.is(TT_SelectorName) || (Right.is(tok::identifier) && Right.Next &&
                                     Right.Next->is(TT_ObjCMethodExpr)))
     return Left.isNot(tok::period); // FIXME: Properly parse ObjC calls.
Index: unittests/Format/FormatTestProto.cpp
===================================================================
--- unittests/Format/FormatTestProto.cpp
+++ unittests/Format/FormatTestProto.cpp
@@ -412,5 +412,14 @@
                "}");
 }
 
+TEST_F(FormatTestProto, KeepsLongStringLiteralsOnSameLine) {
+  verifyFormat(
+      "option (MyProto.options) = {\n"
+      "  foo: {\n"
+      "    text: \"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaasaaaaaaaa\"\n"
+      "  }\n"
+      "}");
+}
+
 } // end namespace tooling
 } // end namespace clang
Index: unittests/Format/FormatTestTextProto.cpp
===================================================================
--- unittests/Format/FormatTestTextProto.cpp
+++ unittests/Format/FormatTestTextProto.cpp
@@ -306,5 +306,12 @@
       "  }\n"
       "}");
 }
+
+TEST_F(FormatTestTextProto, KeepsLongStringLiteralsOnSameLine) {
+  verifyFormat(
+      "foo: {\n"
+      "  text: \"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaasaaaaaaaaaa\"\n"
+      "}");
+}
 } // end namespace tooling
 } // end namespace clang