[Cronet] Make HistogramManager an abstract class to break dependency on native library.

BUG=441466

Review URL: https://codereview.chromium.org/904033004

Cr-Commit-Position: refs/heads/master@{#315108}

components/cronet.gypi

@@ -11,11 +11,11 @@
           'target_name': 'cronet_jni_headers',
           'type': 'none',
           'sources': [
+            'cronet/android/java/src/org/chromium/net/CronetHistogramManager.java',
             'cronet/android/java/src/org/chromium/net/CronetUrlRequest.java',
             'cronet/android/java/src/org/chromium/net/CronetUrlRequestContext.java',
             'cronet/android/java/src/org/chromium/net/ChromiumUrlRequest.java',
             'cronet/android/java/src/org/chromium/net/ChromiumUrlRequestContext.java',
-            'cronet/android/java/src/org/chromium/net/HistogramManager.java',
           ],
           'variables': {
             'jni_gen_package': 'cronet',
@@ -122,6 +122,8 @@
             'cronet/android/chromium_url_request_priority_list.h',
             'cronet/android/chromium_url_request_context.cc',
             'cronet/android/chromium_url_request_context.h',
+            'cronet/android/cronet_histogram_manager.cc',
+            'cronet/android/cronet_histogram_manager.h',
             'cronet/android/cronet_loader.cc',
             'cronet/android/cronet_loader.h',
             'cronet/android/cronet_url_request.cc',
@@ -132,8 +134,6 @@
             'cronet/android/cronet_url_request_context.h',
             'cronet/android/cronet_url_request_context_adapter.cc',
             'cronet/android/cronet_url_request_context_adapter.h',
-            'cronet/android/histogram_manager.cc',
-            'cronet/android/histogram_manager.h',
             'cronet/android/url_request_adapter.cc',
             'cronet/android/url_request_adapter.h',
             'cronet/android/url_request_context_adapter.cc',
@@ -194,6 +194,7 @@
             'javac_includes': [
               '**/ChunkedWritableByteChannel.java',
               '**/ExtendedResponseInfo.java',
+              '**/HistogramManager.java',
               '**/HttpUrlConnection*.java',
               '**/HttpUrlRequest*.java',
               '**/ResponseInfo.java',
@@ -230,11 +231,11 @@
               '**/ChromiumUrlRequestError.java',
               '**/ChromiumUrlRequestFactory.java',
               '**/ChromiumUrlRequestPriority.java',
+              '**/CronetHistogramManager.java',
               '**/CronetResponseInfo.java',
               '**/CronetUrlRequest.java',
               '**/CronetUrlRequestContext.java',
               '**/CronetUrlRequestFactory.java',
-              '**/HistogramManager.java',
               '**/RequestPriority.java',
               '**/urlconnection/CronetInputStream.java',
               '**/urlconnection/CronetHttpURLConnection.java',

components/cronet/android/histogram_manager.cc → components/cronet/android/cronet_histogram_manager.cc

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "components/cronet/android/histogram_manager.h"
+#include "components/cronet/android/cronet_histogram_manager.h"
 
 #include <string>
 #include <vector>
@@ -11,12 +11,12 @@
 #include "base/metrics/statistics_recorder.h"
 #include "components/metrics/histogram_manager.h"
 
-#include "jni/HistogramManager_jni.h"
+#include "jni/CronetHistogramManager_jni.h"
 
 namespace cronet {
 
 // Explicitly register static JNI functions.
-bool HistogramManagerRegisterJni(JNIEnv* env) {
+bool CronetHistogramManagerRegisterJni(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 

components/cronet/android/histogram_manager.h → components/cronet/android/cronet_histogram_manager.h

-// Copyright 2014 The Chromium Authors. All rights reserved.
+// Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
@@ -9,7 +9,7 @@
 
 namespace cronet {
 
-bool HistogramManagerRegisterJni(JNIEnv* env);
+bool CronetHistogramManagerRegisterJni(JNIEnv* env);
 
 }  // namespace cronet
 

components/cronet/android/cronet_loader.cc

@@ -8,9 +8,9 @@
 #include "base/at_exit.h"
 #include "components/cronet/android/chromium_url_request.h"
 #include "components/cronet/android/chromium_url_request_context.h"
+#include "components/cronet/android/cronet_histogram_manager.h"
 #include "components/cronet/android/cronet_url_request.h"
 #include "components/cronet/android/cronet_url_request_context.h"
-#include "components/cronet/android/histogram_manager.h"
 #include "net/android/net_jni_registrar.h"
 #include "url/android/url_jni_registrar.h"
 #include "url/url_util.h"
@@ -24,11 +24,11 @@ namespace {
 
 const base::android::RegistrationMethod kCronetRegisteredMethods[] = {
     {"BaseAndroid", base::android::RegisterJni},
-    {"ChromiumUrlRequest", cronet::ChromiumUrlRequestRegisterJni},
-    {"ChromiumUrlRequestContext", cronet::ChromiumUrlRequestContextRegisterJni},
-    {"CronetUrlRequest", cronet::CronetUrlRequestRegisterJni},
-    {"CronetUrlRequestContext", cronet::CronetUrlRequestContextRegisterJni},
-    {"HistogramManager", cronet::HistogramManagerRegisterJni},
+    {"ChromiumUrlRequest", ChromiumUrlRequestRegisterJni},
+    {"ChromiumUrlRequestContext", ChromiumUrlRequestContextRegisterJni},
+    {"CronetHistogramManager", CronetHistogramManagerRegisterJni},
+    {"CronetUrlRequest", CronetUrlRequestRegisterJni},
+    {"CronetUrlRequestContext", CronetUrlRequestContextRegisterJni},
     {"NetAndroid", net::android::RegisterJni},
     {"UrlAndroid", url::android::RegisterJni},
 };

components/cronet/android/java/src/org/chromium/net/CronetHistogramManager.java

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.net;
+
+import org.chromium.base.JNINamespace;
+
+/**
+ * Controls UMA histograms.
+ */
+@JNINamespace("cronet")
+public final class CronetHistogramManager extends HistogramManager {
+    public CronetHistogramManager() {
+        nativeEnsureInitialized();
+    }
+
+    /**
+     * Get histogram deltas serialized as protobuf.
+     */
+    public byte[] getHistogramDeltas() {
+        return nativeGetHistogramDeltas();
+    }
+
+    private native byte[] nativeGetHistogramDeltas();
+
+    private native void nativeEnsureInitialized();
+}

components/cronet/android/java/src/org/chromium/net/HistogramManager.java

@@ -4,25 +4,41 @@
 
 package org.chromium.net;
 
-import org.chromium.base.JNINamespace;
+import java.lang.reflect.Constructor;
+
 
 /**
- * Controls UMA histograms.
+ * Controls UMA histograms in native library.
  */
-@JNINamespace("cronet")
-public final class HistogramManager {
-    public HistogramManager() {
-        nativeEnsureInitialized();
-    }
+public abstract class HistogramManager {
+    private static final String CRONET_HISTOGRAM_MANAGER =
+            "org.chromium.net.CronetHistogramManager";
 
     /**
      * Get histogram deltas serialized as protobuf.
      */
-    public byte[] getHistogramDeltas() {
-        return nativeGetHistogramDeltas();
-    }
-
-    private native byte[] nativeGetHistogramDeltas();
+    public abstract byte[] getHistogramDeltas();
 
-    private native void nativeEnsureInitialized();
+    /**
+     * Creates Histogram Manager if native library is loaded, returns null if not.
+     */
+    public static HistogramManager createHistogramManager() {
+        HistogramManager histogramManager = null;
+        try {
+            Class<? extends HistogramManager> histogramManagerClass =
+                    HistogramManager.class.getClassLoader()
+                            .loadClass(CRONET_HISTOGRAM_MANAGER)
+                            .asSubclass(HistogramManager.class);
+            Constructor<? extends HistogramManager> constructor =
+                    histogramManagerClass.getConstructor();
+            histogramManager = constructor.newInstance();
+        } catch (ClassNotFoundException e) {
+            // Leave as null.
+        } catch (Exception e) {
+            throw new IllegalStateException(
+                    "Cannot instantiate: " + CRONET_HISTOGRAM_MANAGER,
+                    e);
+        }
+        return histogramManager;
+    }
 }

components/cronet/android/test/src/org/chromium/cronet_test_apk/CronetTestActivity.java

@@ -74,8 +74,6 @@ public class CronetTestActivity extends Activity {
             return;
         }
 
-        mHistogramManager = new HistogramManager();
-
         String skipInitString = getCommandLineArg(SKIP_FACTORY_INIT_KEY);
         if (skipInitString != null) {
             return;
@@ -121,6 +119,8 @@ public class CronetTestActivity extends Activity {
         mUrlRequestContext = UrlRequestContext.createContext(
                 getApplicationContext(), config);
 
+        mHistogramManager = HistogramManager.createHistogramManager();
+
         return HttpUrlRequestFactory.createFactory(getApplicationContext(),
                                                    config);
     }