Add a UMA stat to track if the Browser blacklist is Set on the Renderer

chrome_elf/blacklist/blacklist.cc

Index: chrome_elf/blacklist/blacklist.cc
diff --git a/chrome_elf/blacklist/blacklist.cc b/chrome_elf/blacklist/blacklist.cc
index ea140c4eb532e8966b031a89dc9e6849fefc4925..32d3cb20c632b10a14f15b540bdeceb612d6ea75 100644
--- a/chrome_elf/blacklist/blacklist.cc
+++ b/chrome_elf/blacklist/blacklist.cc
@@ -60,6 +60,10 @@ enum WOW64Status {
   WOW64_UNKNOWN,
 };
 
+// Record if the blacklist was successfully initialized so processes can easily
+// determine if the blacklist is enabled for them.
+bool g_blacklist_initialized = false;
+
 WOW64Status GetWOW64StatusForCurrentProcess() {
   typedef BOOL (WINAPI* IsWow64ProcessFunc)(HANDLE, PBOOL);
   IsWow64ProcessFunc is_wow64_process = reinterpret_cast<IsWow64ProcessFunc>(
@@ -272,6 +276,10 @@ int BlacklistSize() {
   return size;
 }
 
+bool IsBlacklistInitialized() {
+  return g_blacklist_initialized;
+}
+
 bool AddDllToBlacklist(const wchar_t* dll_name) {
   int blacklist_size = BlacklistSize();
   // We need to leave one space at the end for the null pointer.
@@ -373,6 +381,9 @@ bool Initialize(bool force) {
   }
 #endif
 
+  // Record that we have initialized the blacklist.
+  g_blacklist_initialized = true;
+
   BYTE* thunk_storage = reinterpret_cast<BYTE*>(&g_thunk_storage);
 
   // Mark the thunk storage as readable and writeable, since we