Add weekly crash counters, refactor metrics_daemon, respect opt-in in library.

c_metrics_library.h

 // Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef C_METRICS_LIBRARY_H_
 #define C_METRICS_LIBRARY_H_
 
 #if defined(__cplusplus)
 extern "C" {
 #endif
 typedef struct CMetricsLibraryOpaque* CMetricsLibrary;
 
 // C wrapper for MetricsLibrary::MetricsLibrary.
 CMetricsLibrary CMetricsLibraryNew(void);
 
 // C wrapper for MetricsLibrary::~MetricsLibrary.
 void CMetricsLibraryDelete(CMetricsLibrary handle);
 
 // C wrapper for MetricsLibrary::Init.
 void CMetricsLibraryInit(CMetricsLibrary handle);
 
 // C wrapper for MetricsLibrary::SendToUMA.
 int CMetricsLibrarySendToUMA(CMetricsLibrary handle,
-                             const char* name, int sample,
-                             int min, int max, int nbuckets);
+                             const char* name, int sample,
+                             int min, int max, int nbuckets);
 
 // C wrapper for MetricsLibrary::SendEnumToUMA.
 int CMetricsLibrarySendEnumToUMA(CMetricsLibrary handle,
-                                 const char* name, int sample, int max);
+                                 const char* name, int sample, int max);
+
+// C wrapper for MetricsLibrary::AreMetricsEnabled.
+int CMetricsLibraryAreMetricsEnabled(CMetricsLibrary handle);
+
 #if defined(__cplusplus)
 }
 #endif
-#endif  // C_METRICS_LIBRARY_H_
+#endif  // C_METRICS_LIBRARY_H_