Record document mode histogram in UMA on every upload.

chrome/browser/metrics/android_metrics_provider.h

Index: chrome/browser/metrics/android_metrics_provider.h
diff --git a/chrome/browser/metrics/android_metrics_provider.h b/chrome/browser/metrics/android_metrics_provider.h
index 8b004dadf859c21f174c1d89b0e725a86d34cf53..13acca7df3b31b6c6aa84bdd7bc88e26d84f3c3b 100644
--- a/chrome/browser/metrics/android_metrics_provider.h
+++ b/chrome/browser/metrics/android_metrics_provider.h
@@ -12,6 +12,10 @@
 class PrefService;
 class PrefRegistrySimple;
 
+namespace metrics {
+class ChromeUserMetricsExtension;
+}
+
 // AndroidMetricsProvider provides Android-specific stability metrics.
 class AndroidMetricsProvider : public metrics::MetricsProvider {
  public:
@@ -19,11 +23,15 @@ class AndroidMetricsProvider : public metrics::MetricsProvider {
   explicit AndroidMetricsProvider(PrefService* local_state);
   virtual ~AndroidMetricsProvider();
 
+  // metrics::MetricsProvider:
+  virtual void ProvideGeneralMetrics(
+      metrics::ChromeUserMetricsExtension* uma_proto) override;
+
   // Called when the Activity that the user interacts with is swapped out.
   // TODO(asvitkine): Expose a way for Android code to actually invoke this.
   void OnForegroundActivityChanged(ActivityTypeIds::Type type);
 
-  // metrics::MetricsDataProvider:
+  // metrics::MetricsProvider:
   virtual void ProvideStabilityMetrics(
       metrics::SystemProfileProto* system_profile_proto) OVERRIDE;