Add UMA stats to record when DLLs are successfully blocked in the Browser.

chrome_elf/blacklist/blacklist.h

Index: chrome_elf/blacklist/blacklist.h
diff --git a/chrome_elf/blacklist/blacklist.h b/chrome_elf/blacklist/blacklist.h
index 2e21f20793e296cfff766cd3728cf6238f9fe154..49d7e951b4c1cbd91ba63103c061bb4dc4ca2eac 100644
--- a/chrome_elf/blacklist/blacklist.h
+++ b/chrome_elf/blacklist/blacklist.h
@@ -74,6 +74,17 @@ extern "C" bool AddDllToBlacklist(const wchar_t* dll_name);
 // removed, false on error.

[robertshield, 2014/02/25 03:21:40]

Add a comment here and on AddDll* along the lines of "Exposed for testing."

[csharp, 2014/02/25 14:45:00]

Done.

 extern "C" bool RemoveDllFromBlacklist(const wchar_t* dll_name);
 
+// Returns a list of all the dlls that have been successfully blocked by the
+// blacklist via blocked_dlls, if there is enough space (according to |size|).
+// |size| will always be modified to be the number of dlls that were blocked.
+// The caller doesn't own the strings and isn't expected to free them. These
+// strings won't be hanging unless RemoveDllFromBlacklist is called, but it
+// is only exposed in tests (and should stay that way).
+extern "C" void SuccessfullyBlocked(const wchar_t** blocked_dlls, int* size);
+
+// Record that the dll at the given index was blocked.
+void BlockedDll(int blocked_index);
+
 // Initializes the DLL blacklist in the current process. This should be called
 // before any undesirable DLLs might be loaded. If |force| is set to true, then
 // initialization will take place even if a beacon is present. This is useful