[Isolates] Convert more static data either to read-only or to per-isolate.

src/log-utils.h

Index: src/log-utils.h
diff --git a/src/log-utils.h b/src/log-utils.h
index 87ca16810a1e73c8a06365f0c5e329383ac0bc1f..04d1f3af427199bf6c2a4111550333ac600d650e 100644
--- a/src/log-utils.h
+++ b/src/log-utils.h
@@ -163,7 +163,7 @@ class Log {
   static const int kMaxDynamicBufferSize = 50 * 1024 * 1024;
 
   // Message to "seal" dynamic buffer with.
-  static const char* kDynamicBufferSeal;
+  static const char* const kDynamicBufferSeal;
 
   // mutex_ is a Mutex used for enforcing exclusive
   // access to the formatting buffer and the log file or log memory buffer.
@@ -210,8 +210,8 @@ class LogRecordCompressor {
   static const int kNoCompressionWindowSize = 2;
 
   // Formatting strings for back references.
-  static const char* kLineBackwardReferenceFormat;
-  static const char* kBackwardReferenceFormat;
+  static const char* const kLineBackwardReferenceFormat;
+  static const char* const kBackwardReferenceFormat;
 
   static int GetBackwardReferenceSize(int distance, int pos);