Bug 1490525 Part 1 - Remove nsReflowStatus::ToString() r=heycam

This does Bug 1464967 Part 2 in a different way by using mozilla::ToString()
to dump nsReflowStatus.

Differential Revision: https://phabricator.services.mozilla.com/D5634

--HG--
extra : moz-landing-system : lando

layout/generic/nsBlockFrame.cpp

@@ -16,6 +16,7 @@
 #include "mozilla/ComputedStyle.h"
 #include "mozilla/DebugOnly.h"
 #include "mozilla/Maybe.h"
+#include "mozilla/ToString.h"
 #include "mozilla/UniquePtr.h"
 
 #include "nsCOMPtr.h"
@@ -4274,7 +4275,7 @@ nsBlockFrame::ReflowInlineFrame(BlockReflowInput& aState,
 
 #ifdef REALLY_NOISY_REFLOW
   nsFrame::ListTag(stdout, aFrame);
-  printf(": status=%s\n", frameReflowStatus.ToString().get());
+  printf(": status=%s\n", ToString(frameReflowStatus).c_str());
 #endif
 
 #if defined(REFLOW_STATUS_COVERAGE)

layout/generic/nsFrame.cpp

@@ -285,16 +285,6 @@ std::ostream& operator<<(std::ostream& aStream,
   return aStream;
 }
 
-nsCString
-nsReflowStatus::ToString() const
-{
-  nsCString result;
-  std::stringstream ss;
-  ss << *this;
-  result.Append(ss.str().c_str());
-  return result;
-}
-
 static bool gShowFrameBorders = false;
 
 void nsFrame::ShowFrameBorders(bool aEnable)

layout/generic/nsIFrame.h

@@ -356,10 +356,6 @@ public:
   bool FirstLetterComplete() const { return mFirstLetterComplete; }
   void SetFirstLetterComplete() { mFirstLetterComplete = true; }
 
-#ifdef DEBUG
-  nsCString ToString() const;
-#endif
-
 private:
   StyleClear mBreakType;
   InlineBreak mInlineBreak;