Implement a dynamically growing memory log buffer with an upper limit.

src/SConscript

Index: src/SConscript
diff --git a/src/SConscript b/src/SConscript
index 59c452b7ca3fc2f3b54c5010ae69471c645debfd..64d20631caa930b9b637e71f08dc1a0f635209f0 100755
--- a/src/SConscript
+++ b/src/SConscript
@@ -43,14 +43,14 @@ SOURCES = {
     'flags.cc', 'frames.cc', 'func-name-inferrer.cc',
     'global-handles.cc', 'handles.cc', 'hashmap.cc',
     'heap.cc', 'ic.cc', 'interpreter-irregexp.cc', 'jsregexp.cc',
-    'jump-target.cc', 'log.cc', 'mark-compact.cc', 'messages.cc', 'objects.cc',
-    'oprofile-agent.cc', 'parser.cc', 'property.cc', 'regexp-macro-assembler.cc',
-    'regexp-macro-assembler-irregexp.cc', 'regexp-stack.cc',
-    'register-allocator.cc', 'rewriter.cc', 'runtime.cc', 'scanner.cc',
-    'scopeinfo.cc', 'scopes.cc', 'serialize.cc', 'snapshot-common.cc',
-    'spaces.cc', 'string-stream.cc', 'stub-cache.cc', 'token.cc', 'top.cc',
-    'unicode.cc', 'usage-analyzer.cc', 'utils.cc', 'v8-counters.cc',
-    'v8.cc', 'v8threads.cc', 'variables.cc', 'version.cc',
+    'jump-target.cc', 'log.cc', 'log-utils.cc', 'mark-compact.cc', 'messages.cc',
+    'objects.cc', 'oprofile-agent.cc', 'parser.cc', 'property.cc',
+    'regexp-macro-assembler.cc', 'regexp-macro-assembler-irregexp.cc',
+    'regexp-stack.cc', 'register-allocator.cc', 'rewriter.cc', 'runtime.cc',
+    'scanner.cc', 'scopeinfo.cc', 'scopes.cc', 'serialize.cc',
+    'snapshot-common.cc', 'spaces.cc', 'string-stream.cc', 'stub-cache.cc',
+    'token.cc', 'top.cc', 'unicode.cc', 'usage-analyzer.cc', 'utils.cc',
+    'v8-counters.cc', 'v8.cc', 'v8threads.cc', 'variables.cc', 'version.cc',
     'virtual-frame.cc', 'zone.cc'
   ],
   'arch:arm': [