Pass method parameters as JavaParamRef in chrome/browser (part 1).

Pass all object parameters to JNI methods in JavaParamRef<> wrappers.
This matches previous changes made to do this for JNI non-method
functions.

BUG=506850
TBR=sdefresne@chromium.org

Review URL: https://codereview.chromium.org/1510303002

Cr-Commit-Position: refs/heads/master@{#365004}

24 files changed, 449 insertions, 253 deletions

diff --git a/chrome/browser/history/android/sqlite_cursor.cc b/chrome/browser/history/android/sqlite_cursor.cc
index 7b3fa9b..e60bebb 100644
--- a/chrome/browser/history/android/sqlite_cursor.cc
+++ b/chrome/browser/history/android/sqlite_cursor.cc
@@ -60,7 +60,7 @@ bool SQLiteCursor::RegisterSqliteCursor(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
-jint SQLiteCursor::GetCount(JNIEnv* env, jobject obj) {
+jint SQLiteCursor::GetCount(JNIEnv* env, const JavaParamRef<jobject>& obj) {
   // Moves to maxium possible position so we will reach the last row, then finds
   // out the total number of rows.
   int current_position = position_;
@@ -70,34 +70,43 @@ jint SQLiteCursor::GetCount(JNIEnv* env, jobject obj) {
   return count;
 }
 
-ScopedJavaLocalRef<jobjectArray> SQLiteCursor::GetColumnNames(JNIEnv* env,
-                                                              jobject obj) {
+ScopedJavaLocalRef<jobjectArray> SQLiteCursor::GetColumnNames(
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj) {
   return base::android::ToJavaArrayOfStrings(env, column_names_);
 }
 
-ScopedJavaLocalRef<jstring> SQLiteCursor::GetString(JNIEnv* env,
-                                                    jobject obj,
-                                                    jint column) {
+ScopedJavaLocalRef<jstring> SQLiteCursor::GetString(
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj,
+    jint column) {
   base::string16 value = statement_->statement()->ColumnString16(column);
   return ScopedJavaLocalRef<jstring>(env,
       env->NewString(value.data(), value.size()));
 }
 
-jlong SQLiteCursor::GetLong(JNIEnv* env, jobject obj, jint column) {
+jlong SQLiteCursor::GetLong(JNIEnv* env,
+                            const JavaParamRef<jobject>& obj,
+                            jint column) {
   return statement_->statement()->ColumnInt64(column);
 }
 
-jint SQLiteCursor::GetInt(JNIEnv* env, jobject obj, jint column) {
+jint SQLiteCursor::GetInt(JNIEnv* env,
+                          const JavaParamRef<jobject>& obj,
+                          jint column) {
   return statement_->statement()->ColumnInt(column);
 }
 
-jdouble SQLiteCursor::GetDouble(JNIEnv* env, jobject obj, jint column) {
+jdouble SQLiteCursor::GetDouble(JNIEnv* env,
+                                const JavaParamRef<jobject>& obj,
+                                jint column) {
   return statement_->statement()->ColumnDouble(column);
 }
 
-ScopedJavaLocalRef<jbyteArray> SQLiteCursor::GetBlob(JNIEnv* env,
-                                                     jobject obj,
-                                                     jint column) {
+ScopedJavaLocalRef<jbyteArray> SQLiteCursor::GetBlob(
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj,
+    jint column) {
   std::vector<unsigned char> blob;
 
   // Assume the client will only get favicon using GetBlob.
@@ -110,11 +119,15 @@ ScopedJavaLocalRef<jbyteArray> SQLiteCursor::GetBlob(JNIEnv* env,
   return base::android::ToJavaByteArray(env, &blob[0], blob.size());
 }
 
-jboolean SQLiteCursor::IsNull(JNIEnv* env, jobject obj, jint column) {
+jboolean SQLiteCursor::IsNull(JNIEnv* env,
+                              const JavaParamRef<jobject>& obj,
+                              jint column) {
   return NULL_TYPE == GetColumnTypeInternal(column) ? JNI_TRUE : JNI_FALSE;
 }
 
-jint SQLiteCursor::MoveTo(JNIEnv* env, jobject obj, jint pos) {
+jint SQLiteCursor::MoveTo(JNIEnv* env,
+                          const JavaParamRef<jobject>& obj,
+                          jint pos) {
   BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
       base::Bind(&SQLiteCursor::RunMoveStatementOnUIThread,
       base::Unretained(this), pos));
@@ -125,11 +138,13 @@ jint SQLiteCursor::MoveTo(JNIEnv* env, jobject obj, jint pos) {
   return position_;
 }
 
-jint SQLiteCursor::GetColumnType(JNIEnv* env, jobject obj, jint column) {
+jint SQLiteCursor::GetColumnType(JNIEnv* env,
+                                 const JavaParamRef<jobject>& obj,
+                                 jint column) {
   return GetColumnTypeInternal(column);
 }
 
-void SQLiteCursor::Destroy(JNIEnv* env, jobject obj) {
+void SQLiteCursor::Destroy(JNIEnv* env, const JavaParamRef<jobject>& obj) {
   // We do our best to cleanup when Destroy() is called from Java's finalize()
   // where the UI message loop might stop running or in the process of shutting
   // down, as the whole process will be destroyed soon, it's fine to leave some
diff --git a/chrome/browser/history/android/sqlite_cursor.h b/chrome/browser/history/android/sqlite_cursor.h
index c828ad2..f93514a 100644
--- a/chrome/browser/history/android/sqlite_cursor.h
+++ b/chrome/browser/history/android/sqlite_cursor.h
@@ -80,45 +80,59 @@ class SQLiteCursor {
   // JNI methods -----------------------------------------------------------
 
   // Returns the result row count.
-  jint GetCount(JNIEnv* env, jobject obj);
+  jint GetCount(JNIEnv* env, const base::android::JavaParamRef<jobject>& obj);
 
   // Returns the result's columns' name.
   base::android::ScopedJavaLocalRef<jobjectArray> GetColumnNames(
       JNIEnv* env,
-      jobject obj);
+      const base::android::JavaParamRef<jobject>& obj);
 
   // Returns the given column value as jstring.
-  base::android::ScopedJavaLocalRef<jstring> GetString(JNIEnv* env,
-                                                       jobject obj,
-                                                       jint column);
+  base::android::ScopedJavaLocalRef<jstring> GetString(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj,
+      jint column);
 
   // Returns the given column value as jlong.
-  jlong GetLong(JNIEnv* env, jobject obj, jint column);
+  jlong GetLong(JNIEnv* env,
+                const base::android::JavaParamRef<jobject>& obj,
+                jint column);
 
   // Returns the given column value as int.
-  jint GetInt(JNIEnv* env, jobject obj, jint column);
+  jint GetInt(JNIEnv* env,
+              const base::android::JavaParamRef<jobject>& obj,
+              jint column);
 
   // Returns the given column value as double.
-  jdouble GetDouble(JNIEnv* env, jobject obj, jint column);
+  jdouble GetDouble(JNIEnv* env,
+                    const base::android::JavaParamRef<jobject>& obj,
+                    jint column);
 
   // Returns the given column value as jbyteArray.
-  base::android::ScopedJavaLocalRef<jbyteArray> GetBlob(JNIEnv* env,
-                                                        jobject obj,
-                                                        jint column);
+  base::android::ScopedJavaLocalRef<jbyteArray> GetBlob(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj,
+      jint column);
 
   // Return JNI_TRUE if the give column value is NULL, JNI_FALSE otherwise.
-  jboolean IsNull(JNIEnv* env, jobject obj, jint column);
+  jboolean IsNull(JNIEnv* env,
+                  const base::android::JavaParamRef<jobject>& obj,
+                  jint column);
 
   // Moves the cursor to |pos|, returns new position.
   // If the returned position is not equal to |pos|, then the cursor points to
   // the last row.
-  jint MoveTo(JNIEnv* env, jobject obj, jint pos);
+  jint MoveTo(JNIEnv* env,
+              const base::android::JavaParamRef<jobject>& obj,
+              jint pos);
 
   // Returns the type of column.
-  jint GetColumnType(JNIEnv* env, jobject obj, jint column);
+  jint GetColumnType(JNIEnv* env,
+                     const base::android::JavaParamRef<jobject>& obj,
+                     jint column);
 
   // Called from Java to relase this object.
-  void Destroy(JNIEnv* env, jobject obj);
+  void Destroy(JNIEnv* env, const base::android::JavaParamRef<jobject>& obj);
 
  private:
   FRIEND_TEST_ALL_PREFIXES(SQLiteCursorTest, Run);
diff --git a/chrome/browser/media/android/remote/remote_media_player_bridge.cc b/chrome/browser/media/android/remote/remote_media_player_bridge.cc
index 4efd11b..5d3d788 100644
--- a/chrome/browser/media/android/remote/remote_media_player_bridge.cc
+++ b/chrome/browser/media/android/remote/remote_media_player_bridge.cc
@@ -120,19 +120,23 @@ void RemoteMediaPlayerBridge::OnTimeUpdateTimerFired() {
       player_id(), GetCurrentTime(), base::TimeTicks::Now());
 }
 
-void RemoteMediaPlayerBridge::PauseLocal(JNIEnv* env, jobject obj) {
+void RemoteMediaPlayerBridge::PauseLocal(JNIEnv* env,
+                                         const JavaParamRef<jobject>& obj) {
   local_player_->Pause(true);
   static_cast<RemoteMediaPlayerManager*>(manager())->OnPaused(player_id());
 }
 
-jint RemoteMediaPlayerBridge::GetLocalPosition(JNIEnv* env, jobject obj) {
+jint RemoteMediaPlayerBridge::GetLocalPosition(
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj) {
   base::TimeDelta time = local_player_->GetCurrentTime();
   return static_cast<jint>(time.InMilliseconds());
 }
 
-void RemoteMediaPlayerBridge::OnCastStarting(JNIEnv* env,
-                                             jobject obj,
-                                             jstring casting_message) {
+void RemoteMediaPlayerBridge::OnCastStarting(
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj,
+    const JavaParamRef<jstring>& casting_message) {
   static_cast<RemoteMediaPlayerManager*>(manager())->SwitchToRemotePlayer(
       player_id(), ConvertJavaStringToUTF8(env, casting_message));
   if (!time_update_timer_.IsRunning()) {
@@ -143,7 +147,8 @@ void RemoteMediaPlayerBridge::OnCastStarting(JNIEnv* env,
   }
 }
 
-void RemoteMediaPlayerBridge::OnCastStopping(JNIEnv* env, jobject obj) {
+void RemoteMediaPlayerBridge::OnCastStopping(JNIEnv* env,
+                                             const JavaParamRef<jobject>& obj) {
   static_cast<RemoteMediaPlayerManager*>(manager())
       ->SwitchToLocalPlayer(player_id());
 }
@@ -169,32 +174,40 @@ void RemoteMediaPlayerBridge::SetVideoSurface(gfx::ScopedJavaSurface surface) {
 }
 
 base::android::ScopedJavaLocalRef<jstring> RemoteMediaPlayerBridge::GetFrameUrl(
-    JNIEnv* env, jobject obj) {
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj) {
   return ConvertUTF8ToJavaString(env, frame_url().spec());
 }
 
-void RemoteMediaPlayerBridge::OnPlaying(JNIEnv* env, jobject obj) {
+void RemoteMediaPlayerBridge::OnPlaying(JNIEnv* env,
+                                        const JavaParamRef<jobject>& obj) {
   static_cast<RemoteMediaPlayerManager *>(manager())->OnPlaying(player_id());
 }
 
-void RemoteMediaPlayerBridge::OnPaused(JNIEnv* env, jobject obj) {
+void RemoteMediaPlayerBridge::OnPaused(JNIEnv* env,
+                                       const JavaParamRef<jobject>& obj) {
   static_cast<RemoteMediaPlayerManager *>(manager())->OnPaused(player_id());
 }
 
-void RemoteMediaPlayerBridge::OnRouteUnselected(JNIEnv* env, jobject obj) {
+void RemoteMediaPlayerBridge::OnRouteUnselected(
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj) {
   casting_message_.reset();
   static_cast<RemoteMediaPlayerManager *>(manager())->OnRemoteDeviceUnselected(
       player_id());
 }
 
-void RemoteMediaPlayerBridge::OnPlaybackFinished(JNIEnv* env, jobject obj) {
+void RemoteMediaPlayerBridge::OnPlaybackFinished(
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj) {
   static_cast<RemoteMediaPlayerManager *>(manager())->OnRemotePlaybackFinished(
       player_id());
 }
 
-void RemoteMediaPlayerBridge::OnRouteAvailabilityChanged(JNIEnv* env,
-                                                         jobject obj,
-                                                         jboolean available) {
+void RemoteMediaPlayerBridge::OnRouteAvailabilityChanged(
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj,
+    jboolean available) {
   static_cast<RemoteMediaPlayerManager *>(manager())->
       OnRouteAvailabilityChanged(player_id(), available);
 }
@@ -370,7 +383,8 @@ void RemoteMediaPlayerBridge::Initialize() {
 }
 
 base::android::ScopedJavaLocalRef<jstring> RemoteMediaPlayerBridge::GetTitle(
-    JNIEnv* env, jobject obj) {
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj) {
   base::string16 title;
   content::ContentViewCore* core =
       static_cast<RemoteMediaPlayerManager*>(manager())->GetContentViewCore();
diff --git a/chrome/browser/media/android/remote/remote_media_player_bridge.h b/chrome/browser/media/android/remote/remote_media_player_bridge.h
index ea21de7..893d0ff 100644
--- a/chrome/browser/media/android/remote/remote_media_player_bridge.h
+++ b/chrome/browser/media/android/remote/remote_media_player_bridge.h
@@ -56,17 +56,30 @@ class RemoteMediaPlayerBridge : public media::MediaPlayerAndroid {
 
   // JNI functions
   base::android::ScopedJavaLocalRef<jstring> GetFrameUrl(
-      JNIEnv* env, jobject obj);
-  void OnPlaying(JNIEnv* env, jobject obj);
-  void OnPaused(JNIEnv* env, jobject obj);
-  void OnRouteUnselected(JNIEnv* env, jobject obj);
-  void OnPlaybackFinished(JNIEnv* env, jobject obj);
-  void OnRouteAvailabilityChanged(JNIEnv* env, jobject obj, jboolean available);
-  base::android::ScopedJavaLocalRef<jstring> GetTitle(JNIEnv* env, jobject obj);
-  void PauseLocal(JNIEnv* env, jobject obj);
-  jint GetLocalPosition(JNIEnv* env, jobject obj);
-  void OnCastStarting(JNIEnv* env, jobject obj, jstring casting_message);
-  void OnCastStopping(JNIEnv* env, jobject obj);
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj);
+  void OnPlaying(JNIEnv* env, const base::android::JavaParamRef<jobject>& obj);
+  void OnPaused(JNIEnv* env, const base::android::JavaParamRef<jobject>& obj);
+  void OnRouteUnselected(JNIEnv* env,
+                         const base::android::JavaParamRef<jobject>& obj);
+  void OnPlaybackFinished(JNIEnv* env,
+                          const base::android::JavaParamRef<jobject>& obj);
+  void OnRouteAvailabilityChanged(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj,
+      jboolean available);
+  base::android::ScopedJavaLocalRef<jstring> GetTitle(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj);
+  void PauseLocal(JNIEnv* env, const base::android::JavaParamRef<jobject>& obj);
+  jint GetLocalPosition(JNIEnv* env,
+                        const base::android::JavaParamRef<jobject>& obj);
+  void OnCastStarting(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj,
+      const base::android::JavaParamRef<jstring>& casting_message);
+  void OnCastStopping(JNIEnv* env,
+                      const base::android::JavaParamRef<jobject>& obj);
 
   // Wrappers for calls to Java used by the remote media player manager
   void RequestRemotePlayback();
diff --git a/chrome/browser/media/android/router/media_router_android.cc b/chrome/browser/media/android/router/media_router_android.cc
index a3e6e8a..ea91893 100644
--- a/chrome/browser/media/android/router/media_router_android.cc
+++ b/chrome/browser/media/android/router/media_router_android.cc
@@ -314,8 +314,8 @@ void MediaRouterAndroid::UnregisterLocalMediaRoutesObserver(
 
 void MediaRouterAndroid::OnSinksReceived(
     JNIEnv* env,
-    jobject obj,
-    jstring jsource_urn,
+    const JavaParamRef<jobject>& obj,
+    const JavaParamRef<jstring>& jsource_urn,
     jint jcount) {
   std::vector<MediaSink> sinks_converted;
   sinks_converted.reserve(jcount);
@@ -342,9 +342,9 @@ void MediaRouterAndroid::OnSinksReceived(
 
 void MediaRouterAndroid::OnRouteCreated(
     JNIEnv* env,
-    jobject obj,
-    jstring jmedia_route_id,
-    jstring jsink_id,
+    const JavaParamRef<jobject>& obj,
+    const JavaParamRef<jstring>& jmedia_route_id,
+    const JavaParamRef<jstring>& jsink_id,
     jint jroute_request_id,
     jboolean jis_local) {
   MediaRouteRequest* request = route_requests_.Lookup(jroute_request_id);
@@ -369,8 +369,8 @@ void MediaRouterAndroid::OnRouteCreated(
 
 void MediaRouterAndroid::OnRouteRequestError(
     JNIEnv* env,
-    jobject obj,
-    jstring jerror_text,
+    const JavaParamRef<jobject>& obj,
+    const JavaParamRef<jstring>& jerror_text,
     jint jroute_request_id) {
   MediaRouteRequest* request = route_requests_.Lookup(jroute_request_id);
   if (!request)
@@ -384,9 +384,10 @@ void MediaRouterAndroid::OnRouteRequestError(
   route_requests_.Remove(jroute_request_id);
 }
 
-void MediaRouterAndroid::OnRouteClosed(JNIEnv* env,
-                                       jobject obj,
-                                       jstring jmedia_route_id) {
+void MediaRouterAndroid::OnRouteClosed(
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj,
+    const JavaParamRef<jstring>& jmedia_route_id) {
   MediaRoute::Id route_id = ConvertJavaStringToUTF8(env, jmedia_route_id);
   for (auto it = active_routes_.begin(); it != active_routes_.end(); ++it)
     if (it->media_route_id() == route_id) {
@@ -398,16 +399,20 @@ void MediaRouterAndroid::OnRouteClosed(JNIEnv* env,
                     OnRoutesUpdated(active_routes_));
 }
 
-void MediaRouterAndroid::OnMessageSentResult(
-    JNIEnv* env, jobject obj, jboolean jsuccess, jint jcallback_id) {
+void MediaRouterAndroid::OnMessageSentResult(JNIEnv* env,
+                                             const JavaParamRef<jobject>& obj,
+                                             jboolean jsuccess,
+                                             jint jcallback_id) {
   SendRouteMessageCallback* callback = message_callbacks_.Lookup(jcallback_id);
   callback->Run(jsuccess);
   message_callbacks_.Remove(jcallback_id);
 }
 
 // Notifies the media router about a message received from the media route.
-void MediaRouterAndroid::OnMessage(
-    JNIEnv* env, jobject obj, jstring jmedia_route_id, jstring jmessage) {
+void MediaRouterAndroid::OnMessage(JNIEnv* env,
+                                   const JavaParamRef<jobject>& obj,
+                                   const JavaParamRef<jstring>& jmedia_route_id,
+                                   const JavaParamRef<jstring>& jmessage) {
   MediaRoute::Id route_id = ConvertJavaStringToUTF8(env, jmedia_route_id);
   auto* observer_list = messages_observers_.get(route_id);
   if (!observer_list)
diff --git a/chrome/browser/media/android/router/media_router_android.h b/chrome/browser/media/android/router/media_router_android.h
index a2d9b52..25a325a 100644
--- a/chrome/browser/media/android/router/media_router_android.h
+++ b/chrome/browser/media/android/router/media_router_android.h
@@ -57,35 +57,44 @@ class MediaRouterAndroid : public MediaRouterBase {
 
   // Notifies the media router that information about sinks is received for
   // a specific source URN.
-  void OnSinksReceived(
-      JNIEnv* env, jobject obj, jstring jsource_urn, jint jcount);
+  void OnSinksReceived(JNIEnv* env,
+                       const base::android::JavaParamRef<jobject>& obj,
+                       const base::android::JavaParamRef<jstring>& jsource_urn,
+                       jint jcount);
 
   // Notifies the media router about a successful route creation.
   void OnRouteCreated(
       JNIEnv* env,
-      jobject obj,
-      jstring jmedia_route_id,
-      jstring jmedia_sink_id,
+      const base::android::JavaParamRef<jobject>& obj,
+      const base::android::JavaParamRef<jstring>& jmedia_route_id,
+      const base::android::JavaParamRef<jstring>& jmedia_sink_id,
       jint jroute_request_id,
       jboolean jis_local);
 
   // Notifies the media router that route creation or joining failed.
   void OnRouteRequestError(
       JNIEnv* env,
-      jobject obj,
-      jstring jerror_text,
+      const base::android::JavaParamRef<jobject>& obj,
+      const base::android::JavaParamRef<jstring>& jerror_text,
       jint jroute_request_id);
 
   // Notifies the media router when the route was closed.
-  void OnRouteClosed(JNIEnv* env, jobject obj, jstring jmedia_route_id);
+  void OnRouteClosed(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj,
+      const base::android::JavaParamRef<jstring>& jmedia_route_id);
 
   // Notifies the media router about the result of sending a message.
-  void OnMessageSentResult(
-      JNIEnv* env, jobject obj, jboolean jsuccess, jint jcallback_id);
+  void OnMessageSentResult(JNIEnv* env,
+                           const base::android::JavaParamRef<jobject>& obj,
+                           jboolean jsuccess,
+                           jint jcallback_id);
 
   // Notifies the media router about a message received from the media route.
-  void OnMessage(
-      JNIEnv* env, jobject obj, jstring jmedia_route_id, jstring jmessage);
+  void OnMessage(JNIEnv* env,
+                 const base::android::JavaParamRef<jobject>& obj,
+                 const base::android::JavaParamRef<jstring>& jmedia_route_id,
+                 const base::android::JavaParamRef<jstring>& jmessage);
 
  private:
   friend class MediaRouterFactory;
diff --git a/chrome/browser/media/android/router/media_router_dialog_controller_android.cc b/chrome/browser/media/android/router/media_router_dialog_controller_android.cc
index cbff49e..86ab932 100644
--- a/chrome/browser/media/android/router/media_router_dialog_controller_android.cc
+++ b/chrome/browser/media/android/router/media_router_dialog_controller_android.cc
@@ -36,7 +36,9 @@ MediaRouterDialogControllerAndroid::GetOrCreateForWebContents(
 }
 
 void MediaRouterDialogControllerAndroid::OnSinkSelected(
-    JNIEnv* env, jobject obj, jstring jsink_id) {
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj,
+    const JavaParamRef<jstring>& jsink_id) {
   scoped_ptr<CreatePresentationConnectionRequest> create_connection_request =
       TakeCreateConnectionRequest();
   const PresentationRequest& presentation_request =
@@ -61,8 +63,8 @@ void MediaRouterDialogControllerAndroid::OnSinkSelected(
 
 void MediaRouterDialogControllerAndroid::OnRouteClosed(
     JNIEnv* env,
-    jobject obj,
-    jstring jmedia_route_id) {
+    const JavaParamRef<jobject>& obj,
+    const JavaParamRef<jstring>& jmedia_route_id) {
   std::string media_route_id = ConvertJavaStringToUTF8(env, jmedia_route_id);
 
   MediaRouter* router = MediaRouterFactory::GetApiForBrowserContext(
@@ -74,7 +76,8 @@ void MediaRouterDialogControllerAndroid::OnRouteClosed(
 }
 
 void MediaRouterDialogControllerAndroid::OnDialogCancelled(
-    JNIEnv* env, jobject obj) {
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj) {
   CancelPresentationRequest();
 }
 
diff --git a/chrome/browser/media/android/router/media_router_dialog_controller_android.h b/chrome/browser/media/android/router/media_router_dialog_controller_android.h
index cbd5928..40c8c02 100644
--- a/chrome/browser/media/android/router/media_router_dialog_controller_android.h
+++ b/chrome/browser/media/android/router/media_router_dialog_controller_android.h
@@ -32,12 +32,18 @@ class MediaRouterDialogControllerAndroid
   // The methods called by the Java counterpart.
 
   // Notifies the controller that user has selected a sink with |jsink_id|.
-  void OnSinkSelected(JNIEnv* env, jobject obj, jstring jsink_id);
+  void OnSinkSelected(JNIEnv* env,
+                      const base::android::JavaParamRef<jobject>& obj,
+                      const base::android::JavaParamRef<jstring>& jsink_id);
   // Notifies the controller that user chose to close the route.
-  void OnRouteClosed(JNIEnv* env, jobject obj, jstring jmedia_route_id);
+  void OnRouteClosed(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj,
+      const base::android::JavaParamRef<jstring>& jmedia_route_id);
   // Notifies the controller that the dialog has been closed without the user
   // taking any action (e.g. closing the route or selecting a sink).
-  void OnDialogCancelled(JNIEnv* env, jobject obj);
+  void OnDialogCancelled(JNIEnv* env,
+                         const base::android::JavaParamRef<jobject>& obj);
 
  private:
   friend class content::WebContentsUserData<MediaRouterDialogControllerAndroid>;
diff --git a/chrome/browser/net/spdyproxy/data_reduction_proxy_settings_android.cc b/chrome/browser/net/spdyproxy/data_reduction_proxy_settings_android.cc
index cbd5130..6090293 100644
--- a/chrome/browser/net/spdyproxy/data_reduction_proxy_settings_android.cc
+++ b/chrome/browser/net/spdyproxy/data_reduction_proxy_settings_android.cc
@@ -32,76 +32,90 @@ DataReductionProxySettingsAndroid::~DataReductionProxySettingsAndroid() {
 }
 
 jboolean DataReductionProxySettingsAndroid::IsDataReductionProxyAllowed(
-    JNIEnv* env, jobject obj) {
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj) {
   return Settings()->Allowed();
 }
 
 jboolean DataReductionProxySettingsAndroid::IsDataReductionProxyPromoAllowed(
-    JNIEnv* env, jobject obj) {
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj) {
   return Settings()->PromoAllowed();
 }
 
 jboolean DataReductionProxySettingsAndroid::IsIncludedInAltFieldTrial(
-    JNIEnv* env, jobject obj) {
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj) {
   return false;
 }
 
 jboolean DataReductionProxySettingsAndroid::IsDataReductionProxyEnabled(
-    JNIEnv* env, jobject obj) {
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj) {
   return Settings()->IsDataReductionProxyEnabled();
 }
 
 jboolean DataReductionProxySettingsAndroid::CanUseDataReductionProxy(
-    JNIEnv* env, jobject obj, jstring url) {
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj,
+    const JavaParamRef<jstring>& url) {
   return Settings()->CanUseDataReductionProxy(
       GURL(base::android::ConvertJavaStringToUTF16(env, url)));
 }
 
 jboolean DataReductionProxySettingsAndroid::WasLoFiModeActiveOnMainFrame(
-    JNIEnv* env, jobject obj) {
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj) {
   return Settings()->WasLoFiModeActiveOnMainFrame();
 }
 
 jboolean DataReductionProxySettingsAndroid::WasLoFiLoadImageRequestedBefore(
-    JNIEnv* env, jobject obj) {
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj) {
   return Settings()->WasLoFiLoadImageRequestedBefore();
 }
 
 void DataReductionProxySettingsAndroid::SetLoFiLoadImageRequested(
-    JNIEnv* env, jobject obj) {
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj) {
   Settings()->SetLoFiLoadImageRequested();
 }
 
 jboolean DataReductionProxySettingsAndroid::IsDataReductionProxyManaged(
-    JNIEnv* env, jobject obj) {
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj) {
   return Settings()->IsDataReductionProxyManaged();
 }
 
 void DataReductionProxySettingsAndroid::IncrementLoFiSnackbarShown(
-    JNIEnv* env, jobject obj) {
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj) {
   Settings()->IncrementLoFiSnackbarShown();
 }
 
 void DataReductionProxySettingsAndroid::IncrementLoFiUserRequestsForImages(
-    JNIEnv* env, jobject obj) {
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj) {
   Settings()->IncrementLoFiUserRequestsForImages();
 }
 
 void DataReductionProxySettingsAndroid::SetDataReductionProxyEnabled(
     JNIEnv* env,
-    jobject obj,
+    const JavaParamRef<jobject>& obj,
     jboolean enabled) {
   Settings()->SetDataReductionProxyEnabled(enabled);
 }
 
 jlong DataReductionProxySettingsAndroid::GetDataReductionLastUpdateTime(
-    JNIEnv* env, jobject obj) {
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj) {
   return Settings()->GetDataReductionLastUpdateTime();
 }
 
 base::android::ScopedJavaLocalRef<jobject>
-DataReductionProxySettingsAndroid::GetContentLengths(JNIEnv* env,
-                                                     jobject obj) {
+DataReductionProxySettingsAndroid::GetContentLengths(
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj) {
   int64 original_content_length;
   int64 received_content_length;
   int64 last_update_internal;
@@ -118,20 +132,23 @@ DataReductionProxySettingsAndroid::GetContentLengths(JNIEnv* env,
 
 ScopedJavaLocalRef<jlongArray>
 DataReductionProxySettingsAndroid::GetDailyOriginalContentLengths(
-    JNIEnv* env, jobject obj) {
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj) {
   return GetDailyContentLengths(
       env, data_reduction_proxy::prefs::kDailyHttpOriginalContentLength);
 }
 
 ScopedJavaLocalRef<jlongArray>
 DataReductionProxySettingsAndroid::GetDailyReceivedContentLengths(
-    JNIEnv* env, jobject obj) {
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj) {
   return GetDailyContentLengths(
       env, data_reduction_proxy::prefs::kDailyHttpReceivedContentLength);
 }
 
 jboolean DataReductionProxySettingsAndroid::IsDataReductionProxyUnreachable(
-    JNIEnv* env, jobject obj) {
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj) {
   return Settings()->IsDataReductionProxyUnreachable();
 }
 
@@ -160,7 +177,7 @@ DataReductionProxySettingsAndroid::GetDailyContentLengths(
 
 ScopedJavaLocalRef<jstring> DataReductionProxySettingsAndroid::GetHttpProxyList(
     JNIEnv* env,
-    jobject obj) {
+    const JavaParamRef<jobject>& obj) {
   data_reduction_proxy::DataReductionProxyEventStore* event_store =
       Settings()->GetEventStore();
   if (!event_store)
@@ -170,7 +187,9 @@ ScopedJavaLocalRef<jstring> DataReductionProxySettingsAndroid::GetHttpProxyList(
 }
 
 ScopedJavaLocalRef<jstring>
-DataReductionProxySettingsAndroid::GetHttpsProxyList(JNIEnv* env, jobject obj) {
+DataReductionProxySettingsAndroid::GetHttpsProxyList(
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj) {
   data_reduction_proxy::DataReductionProxyEventStore* event_store =
       Settings()->GetEventStore();
   if (!event_store)
@@ -188,8 +207,9 @@ DataReductionProxySettings* DataReductionProxySettingsAndroid::Settings() {
 }
 
 ScopedJavaLocalRef<jstring>
-DataReductionProxySettingsAndroid::GetLastBypassEvent(JNIEnv* env,
-                                                      jobject obj) {
+DataReductionProxySettingsAndroid::GetLastBypassEvent(
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj) {
   data_reduction_proxy::DataReductionProxyEventStore* event_store =
       Settings()->GetEventStore();
   if (!event_store)
diff --git a/chrome/browser/net/spdyproxy/data_reduction_proxy_settings_android.h b/chrome/browser/net/spdyproxy/data_reduction_proxy_settings_android.h
index e79be28..2512284 100644
--- a/chrome/browser/net/spdyproxy/data_reduction_proxy_settings_android.h
+++ b/chrome/browser/net/spdyproxy/data_reduction_proxy_settings_android.h
@@ -34,34 +34,67 @@ class DataReductionProxySettingsAndroid {
   void InitDataReductionProxySettings(Profile* profile);
 
   // JNI wrapper interfaces to the indentically-named superclass methods.
-  jboolean IsDataReductionProxyAllowed(JNIEnv* env, jobject obj);
-  jboolean IsDataReductionProxyPromoAllowed(JNIEnv* env, jobject obj);
-  jboolean IsIncludedInAltFieldTrial(JNIEnv* env, jobject obj);
-  jboolean IsDataReductionProxyEnabled(JNIEnv* env, jobject obj);
-  jboolean CanUseDataReductionProxy(JNIEnv* env, jobject obj, jstring url);
-  jboolean WasLoFiModeActiveOnMainFrame(JNIEnv* env, jobject obj);
-  jboolean WasLoFiLoadImageRequestedBefore(JNIEnv* env, jobject obj);
-  void SetLoFiLoadImageRequested(JNIEnv* env, jobject obj);
-  jboolean IsDataReductionProxyManaged(JNIEnv* env, jobject obj);
-  void IncrementLoFiSnackbarShown(JNIEnv* env, jobject obj);
-  void IncrementLoFiUserRequestsForImages(JNIEnv* env, jobject obj);
-  void SetDataReductionProxyEnabled(JNIEnv* env, jobject obj, jboolean enabled);
-
-  jlong GetDataReductionLastUpdateTime(JNIEnv* env, jobject obj);
-  ScopedJavaLocalRef<jlongArray> GetDailyOriginalContentLengths(JNIEnv* env,
-                                                                jobject obj);
-  ScopedJavaLocalRef<jlongArray> GetDailyReceivedContentLengths(JNIEnv* env,
-                                                                jobject obj);
+  jboolean IsDataReductionProxyAllowed(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj);
+  jboolean IsDataReductionProxyPromoAllowed(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj);
+  jboolean IsIncludedInAltFieldTrial(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj);
+  jboolean IsDataReductionProxyEnabled(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj);
+  jboolean CanUseDataReductionProxy(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj,
+      const base::android::JavaParamRef<jstring>& url);
+  jboolean WasLoFiModeActiveOnMainFrame(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj);
+  jboolean WasLoFiLoadImageRequestedBefore(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj);
+  void SetLoFiLoadImageRequested(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj);
+  jboolean IsDataReductionProxyManaged(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj);
+  void IncrementLoFiSnackbarShown(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj);
+  void IncrementLoFiUserRequestsForImages(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj);
+  void SetDataReductionProxyEnabled(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj,
+      jboolean enabled);
+
+  jlong GetDataReductionLastUpdateTime(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj);
+  ScopedJavaLocalRef<jlongArray> GetDailyOriginalContentLengths(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj);
+  ScopedJavaLocalRef<jlongArray> GetDailyReceivedContentLengths(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj);
 
   // Return a Java |ContentLengths| object wrapping the results of a call to
   // DataReductionProxySettings::GetContentLengths.
-  base::android::ScopedJavaLocalRef<jobject> GetContentLengths(JNIEnv* env,
-                                                               jobject obj);
+  base::android::ScopedJavaLocalRef<jobject> GetContentLengths(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj);
 
   // Determines whether the data reduction proxy is unreachable. This is
   // done by keeping a count of requests which go through proxy vs those
   // which should have gone through the proxy based on the config.
-  jboolean IsDataReductionProxyUnreachable(JNIEnv* env, jobject obj);
+  jboolean IsDataReductionProxyUnreachable(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj);
 
   ScopedJavaLocalRef<jstring> GetTokenForAuthChallenge(JNIEnv* env,
                                                        jobject obj,
@@ -70,15 +103,21 @@ class DataReductionProxySettingsAndroid {
 
   // Returns a Java string of the Data Reduction Proxy proxy list for HTTP
   // origins as a semi-colon delimited list.
-  ScopedJavaLocalRef<jstring> GetHttpProxyList(JNIEnv* env, jobject obj);
+  ScopedJavaLocalRef<jstring> GetHttpProxyList(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj);
 
   // Returns a Java string of the Data Reduction Proxy proxy list for HTTPS
   // origins as a semi-colon delimited list.
-  ScopedJavaLocalRef<jstring> GetHttpsProxyList(JNIEnv* env, jobject obj);
+  ScopedJavaLocalRef<jstring> GetHttpsProxyList(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj);
 
   // Returns a Java string of the last Data Reduction Proxy bypass event as
   // a JSON object.
-  ScopedJavaLocalRef<jstring> GetLastBypassEvent(JNIEnv* env, jobject obj);
+  ScopedJavaLocalRef<jstring> GetLastBypassEvent(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj);
 
   // Registers the native methods to be call from Java.
   static bool Register(JNIEnv* env);
diff --git a/chrome/browser/notifications/notification_ui_manager_android.cc b/chrome/browser/notifications/notification_ui_manager_android.cc
index 9943969..cf2b78a 100644
--- a/chrome/browser/notifications/notification_ui_manager_android.cc
+++ b/chrome/browser/notifications/notification_ui_manager_android.cc
@@ -55,10 +55,10 @@ NotificationUIManagerAndroid::~NotificationUIManagerAndroid() {
 
 bool NotificationUIManagerAndroid::OnNotificationClicked(
     JNIEnv* env,
-    jobject java_object,
+    const JavaParamRef<jobject>& java_object,
     jlong persistent_notification_id,
-    jstring java_origin,
-    jstring java_tag,
+    const JavaParamRef<jstring>& java_origin,
+    const JavaParamRef<jstring>& java_tag,
     jint action_index) {
   GURL origin(ConvertJavaStringToUTF8(env, java_origin));
   std::string tag = ConvertJavaStringToUTF8(env, java_tag);
@@ -80,10 +80,10 @@ bool NotificationUIManagerAndroid::OnNotificationClicked(
 
 bool NotificationUIManagerAndroid::OnNotificationClosed(
     JNIEnv* env,
-    jobject java_object,
+    const JavaParamRef<jobject>& java_object,
     jlong persistent_notification_id,
-    jstring java_origin,
-    jstring java_tag,
+    const JavaParamRef<jstring>& java_origin,
+    const JavaParamRef<jstring>& java_tag,
     jboolean by_user) {
   GURL origin(ConvertJavaStringToUTF8(env, java_origin));
   std::string tag = ConvertJavaStringToUTF8(env, java_tag);
diff --git a/chrome/browser/notifications/notification_ui_manager_android.h b/chrome/browser/notifications/notification_ui_manager_android.h
index 41a0af3..33f37f3 100644
--- a/chrome/browser/notifications/notification_ui_manager_android.h
+++ b/chrome/browser/notifications/notification_ui_manager_android.h
@@ -30,20 +30,22 @@ class NotificationUIManagerAndroid : public NotificationUIManager {
   ~NotificationUIManagerAndroid() override;
 
   // Called by the Java implementation when the notification has been clicked.
-  bool OnNotificationClicked(JNIEnv* env,
-                             jobject java_object,
-                             jlong persistent_notification_id,
-                             jstring java_origin,
-                             jstring java_tag,
-                             jint action_index);
+  bool OnNotificationClicked(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& java_object,
+      jlong persistent_notification_id,
+      const base::android::JavaParamRef<jstring>& java_origin,
+      const base::android::JavaParamRef<jstring>& java_tag,
+      jint action_index);
 
   // Called by the Java implementation when the notification has been closed.
-  bool OnNotificationClosed(JNIEnv* env,
-                            jobject java_object,
-                            jlong persistent_notification_id,
-                            jstring java_origin,
-                            jstring java_tag,
-                            jboolean by_user);
+  bool OnNotificationClosed(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& java_object,
+      jlong persistent_notification_id,
+      const base::android::JavaParamRef<jstring>& java_origin,
+      const base::android::JavaParamRef<jstring>& java_tag,
+      jboolean by_user);
 
   // NotificationUIManager implementation.
   void Add(const Notification& notification, Profile* profile) override;
diff --git a/chrome/browser/permissions/permission_update_infobar_delegate_android.cc b/chrome/browser/permissions/permission_update_infobar_delegate_android.cc
index 4a876d1..1999ae0 100644
--- a/chrome/browser/permissions/permission_update_infobar_delegate_android.cc
+++ b/chrome/browser/permissions/permission_update_infobar_delegate_android.cc
@@ -119,7 +119,9 @@ bool PermissionUpdateInfoBarDelegate::RegisterPermissionUpdateInfoBarDelegate(
 }
 
 void PermissionUpdateInfoBarDelegate::OnPermissionResult(
-    JNIEnv* env, jobject obj, jboolean all_permissions_granted) {
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj,
+    jboolean all_permissions_granted) {
   base::ResetAndReturn(&callback_).Run(all_permissions_granted);
   infobar()->RemoveSelf();
 }
diff --git a/chrome/browser/permissions/permission_update_infobar_delegate_android.h b/chrome/browser/permissions/permission_update_infobar_delegate_android.h
index dc3b1cb..34db3c7 100644
--- a/chrome/browser/permissions/permission_update_infobar_delegate_android.h
+++ b/chrome/browser/permissions/permission_update_infobar_delegate_android.h
@@ -55,8 +55,9 @@ class PermissionUpdateInfoBarDelegate : public ConfirmInfoBarDelegate {
 
   static bool RegisterPermissionUpdateInfoBarDelegate(JNIEnv* env);
 
-  void OnPermissionResult(
-      JNIEnv* env, jobject obj, jboolean all_permissions_granted);
+  void OnPermissionResult(JNIEnv* env,
+                          const base::android::JavaParamRef<jobject>& obj,
+                          jboolean all_permissions_granted);
 
  private:
   PermissionUpdateInfoBarDelegate(
diff --git a/chrome/browser/prerender/external_prerender_handler_android.cc b/chrome/browser/prerender/external_prerender_handler_android.cc
index e02dfee..8714710 100644
--- a/chrome/browser/prerender/external_prerender_handler_android.cc
+++ b/chrome/browser/prerender/external_prerender_handler_android.cc
@@ -22,14 +22,15 @@ using base::android::ConvertJavaStringToUTF16;
 
 namespace prerender {
 
-bool ExternalPrerenderHandlerAndroid::AddPrerender(JNIEnv* env,
-                                                   jobject obj,
-                                                   jobject jprofile,
-                                                   jobject jweb_contents,
-                                                   jstring jurl,
-                                                   jstring jreferrer,
-                                                   jint width,
-                                                   jint height) {
+bool ExternalPrerenderHandlerAndroid::AddPrerender(
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj,
+    const JavaParamRef<jobject>& jprofile,
+    const JavaParamRef<jobject>& jweb_contents,
+    const JavaParamRef<jstring>& jurl,
+    const JavaParamRef<jstring>& jreferrer,
+    jint width,
+    jint height) {
   Profile* profile = ProfileAndroid::FromProfileAndroid(jprofile);
 
   GURL url = GURL(ConvertJavaStringToUTF16(env, jurl));
@@ -60,8 +61,9 @@ bool ExternalPrerenderHandlerAndroid::AddPrerender(JNIEnv* env,
   return true;
 }
 
-void ExternalPrerenderHandlerAndroid::CancelCurrentPrerender(JNIEnv* env,
-                                                             jobject object) {
+void ExternalPrerenderHandlerAndroid::CancelCurrentPrerender(
+    JNIEnv* env,
+    const JavaParamRef<jobject>& object) {
   if (!prerender_handle_)
     return;
   prerender_handle_->OnCancel();
diff --git a/chrome/browser/prerender/external_prerender_handler_android.h b/chrome/browser/prerender/external_prerender_handler_android.h
index 329dac4..4430cbc 100644
--- a/chrome/browser/prerender/external_prerender_handler_android.h
+++ b/chrome/browser/prerender/external_prerender_handler_android.h
@@ -28,16 +28,18 @@ class ExternalPrerenderHandlerAndroid {
   // Add a prerender with the given url and referrer on the PrerenderManager of
   // the given profile. This is restricted to a single prerender at a time.
   bool AddPrerender(JNIEnv* env,
-                    jobject obj,
-                    jobject profile,
-                    jobject jweb_contents,
-                    jstring url,
-                    jstring referrer,
+                    const base::android::JavaParamRef<jobject>& obj,
+                    const base::android::JavaParamRef<jobject>& profile,
+                    const base::android::JavaParamRef<jobject>& jweb_contents,
+                    const base::android::JavaParamRef<jstring>& url,
+                    const base::android::JavaParamRef<jstring>& referrer,
                     jint width,
                     jint height);
 
   // Cancel the prerender associated with the prerender_handle_
-  void CancelCurrentPrerender(JNIEnv* env, jobject object);
+  void CancelCurrentPrerender(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& object);
 
   // Whether the PrerenderManager associated with the given profile has any
   // prerenders for the url.
diff --git a/chrome/browser/profiles/profile_android.cc b/chrome/browser/profiles/profile_android.cc
index 9c92901..2ec4bbb 100644
--- a/chrome/browser/profiles/profile_android.cc
+++ b/chrome/browser/profiles/profile_android.cc
@@ -65,14 +65,16 @@ ScopedJavaLocalRef<jobject> ProfileAndroid::GetLastUsedProfile(JNIEnv* env,
   return ScopedJavaLocalRef<jobject>(profile_android->obj_);
 }
 
-void ProfileAndroid::DestroyWhenAppropriate(JNIEnv* env, jobject obj) {
+void ProfileAndroid::DestroyWhenAppropriate(JNIEnv* env,
+                                            const JavaParamRef<jobject>& obj) {
   // Don't delete the Profile directly because the corresponding
   // RenderViewHost might not be deleted yet.
   ProfileDestroyer::DestroyProfileWhenAppropriate(profile_);
 }
 
 base::android::ScopedJavaLocalRef<jobject> ProfileAndroid::GetOriginalProfile(
-    JNIEnv* env, jobject obj) {
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj) {
   ProfileAndroid* original_profile = ProfileAndroid::FromProfile(
       profile_->GetOriginalProfile());
   DCHECK(original_profile);
@@ -80,18 +82,22 @@ base::android::ScopedJavaLocalRef<jobject> ProfileAndroid::GetOriginalProfile(
 }
 
 base::android::ScopedJavaLocalRef<jobject>
-ProfileAndroid::GetOffTheRecordProfile(JNIEnv* env, jobject obj) {
+ProfileAndroid::GetOffTheRecordProfile(JNIEnv* env,
+                                       const JavaParamRef<jobject>& obj) {
   ProfileAndroid* otr_profile = ProfileAndroid::FromProfile(
       profile_->GetOffTheRecordProfile());
   DCHECK(otr_profile);
   return otr_profile->GetJavaObject();
 }
 
-jboolean ProfileAndroid::HasOffTheRecordProfile(JNIEnv* env, jobject obj) {
+jboolean ProfileAndroid::HasOffTheRecordProfile(
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj) {
   return profile_->HasOffTheRecordProfile();
 }
 
-jboolean ProfileAndroid::IsOffTheRecord(JNIEnv* env, jobject obj) {
+jboolean ProfileAndroid::IsOffTheRecord(JNIEnv* env,
+                                        const JavaParamRef<jobject>& obj) {
   return profile_->IsOffTheRecord();
 }
 
diff --git a/chrome/browser/profiles/profile_android.h b/chrome/browser/profiles/profile_android.h
index e6ed2c8..b7a55d3 100644
--- a/chrome/browser/profiles/profile_android.h
+++ b/chrome/browser/profiles/profile_android.h
@@ -26,11 +26,13 @@ class ProfileAndroid : public base::SupportsUserData::Data {
       jclass clazz);
 
   // Destroys this Profile when possible.
-  void DestroyWhenAppropriate(JNIEnv* env, jobject obj);
+  void DestroyWhenAppropriate(JNIEnv* env,
+                              const base::android::JavaParamRef<jobject>& obj);
 
   // Return the original profile.
   base::android::ScopedJavaLocalRef<jobject> GetOriginalProfile(
-      JNIEnv* env, jobject obj);
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj);
 
   // Return the incognito profile.
   //
@@ -38,13 +40,17 @@ class ProfileAndroid : public base::SupportsUserData::Data {
   // exist. If this isn't what you want, you need to check
   // HasOffTheRecordProfile() first.
   base::android::ScopedJavaLocalRef<jobject> GetOffTheRecordProfile(
-      JNIEnv* env, jobject obj);
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj);
 
   // Return whether an off the record profile exists.
-  jboolean HasOffTheRecordProfile(JNIEnv* env, jobject obj);
+  jboolean HasOffTheRecordProfile(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj);
 
   // Whether this profile is off the record.
-  jboolean IsOffTheRecord(JNIEnv* env, jobject obj);
+  jboolean IsOffTheRecord(JNIEnv* env,
+                          const base::android::JavaParamRef<jobject>& obj);
 
   explicit ProfileAndroid(Profile* profile);
   ~ProfileAndroid() override;
diff --git a/chrome/browser/search_engines/template_url_service_android.cc b/chrome/browser/search_engines/template_url_service_android.cc
index 8ab11e0..8e88588 100644
--- a/chrome/browser/search_engines/template_url_service_android.cc
+++ b/chrome/browser/search_engines/template_url_service_android.cc
@@ -44,13 +44,14 @@ TemplateUrlServiceAndroid::~TemplateUrlServiceAndroid() {
   template_url_service_->RemoveObserver(this);
 }
 
-void TemplateUrlServiceAndroid::Load(JNIEnv* env, jobject obj) {
+void TemplateUrlServiceAndroid::Load(JNIEnv* env,
+                                     const JavaParamRef<jobject>& obj) {
   template_url_service_->Load();
 }
 
 void TemplateUrlServiceAndroid::SetUserSelectedDefaultSearchProvider(
     JNIEnv* env,
-    jobject obj,
+    const JavaParamRef<jobject>& obj,
     jint selected_index) {
   std::vector<TemplateURL*> template_urls =
       template_url_service_->GetTemplateURLs();
@@ -64,8 +65,9 @@ void TemplateUrlServiceAndroid::SetUserSelectedDefaultSearchProvider(
   template_url_service_->SetUserSelectedDefaultSearchProvider(template_url);
 }
 
-jint TemplateUrlServiceAndroid::GetDefaultSearchProvider(JNIEnv* env,
-                                                         jobject obj) {
+jint TemplateUrlServiceAndroid::GetDefaultSearchProvider(
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj) {
   std::vector<TemplateURL*> template_urls =
       template_url_service_->GetTemplateURLs();
   TemplateURL* default_search_provider =
@@ -77,21 +79,26 @@ jint TemplateUrlServiceAndroid::GetDefaultSearchProvider(JNIEnv* env,
   return -1;
 }
 
-jboolean TemplateUrlServiceAndroid::IsLoaded(JNIEnv* env, jobject obj) {
+jboolean TemplateUrlServiceAndroid::IsLoaded(JNIEnv* env,
+                                             const JavaParamRef<jobject>& obj) {
   return template_url_service_->loaded();
 }
 
-jint TemplateUrlServiceAndroid::GetTemplateUrlCount(JNIEnv* env, jobject obj) {
+jint TemplateUrlServiceAndroid::GetTemplateUrlCount(
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj) {
   return template_url_service_->GetTemplateURLs().size();
 }
 
-jboolean TemplateUrlServiceAndroid::IsSearchProviderManaged(JNIEnv* env,
-                                                            jobject obj) {
+jboolean TemplateUrlServiceAndroid::IsSearchProviderManaged(
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj) {
   return template_url_service_->is_default_search_managed();
 }
 
-jboolean TemplateUrlServiceAndroid::IsSearchByImageAvailable(JNIEnv* env,
-                                                             jobject obj) {
+jboolean TemplateUrlServiceAndroid::IsSearchByImageAvailable(
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj) {
   const TemplateURL* default_search_provider =
       template_url_service_->GetDefaultSearchProvider();
   return default_search_provider &&
@@ -100,8 +107,9 @@ jboolean TemplateUrlServiceAndroid::IsSearchByImageAvailable(JNIEnv* env,
           template_url_service_->search_terms_data());
 }
 
-jboolean TemplateUrlServiceAndroid::IsDefaultSearchEngineGoogle(JNIEnv* env,
-                                                                jobject obj) {
+jboolean TemplateUrlServiceAndroid::IsDefaultSearchEngineGoogle(
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj) {
   TemplateURL* default_search_provider =
       template_url_service_->GetDefaultSearchProvider();
   return default_search_provider &&
@@ -110,9 +118,10 @@ jboolean TemplateUrlServiceAndroid::IsDefaultSearchEngineGoogle(JNIEnv* env,
 }
 
 base::android::ScopedJavaLocalRef<jobject>
-TemplateUrlServiceAndroid::GetPrepopulatedTemplateUrlAt(JNIEnv* env,
-                                                        jobject obj,
-                                                        jint index) {
+TemplateUrlServiceAndroid::GetPrepopulatedTemplateUrlAt(
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj,
+    jint index) {
   TemplateURL* template_url = template_url_service_->GetTemplateURLs()[index];
   if (!IsPrepopulatedTemplate(template_url) &&
       !template_url->created_by_policy())
@@ -149,9 +158,10 @@ void TemplateUrlServiceAndroid::OnTemplateURLServiceChanged() {
 }
 
 base::android::ScopedJavaLocalRef<jstring>
-TemplateUrlServiceAndroid::GetUrlForSearchQuery(JNIEnv* env,
-                                                jobject obj,
-                                                jstring jquery) {
+TemplateUrlServiceAndroid::GetUrlForSearchQuery(
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj,
+    const JavaParamRef<jstring>& jquery) {
   const TemplateURL* default_provider =
       template_url_service_->GetDefaultSearchProvider();
 
@@ -171,9 +181,10 @@ TemplateUrlServiceAndroid::GetUrlForSearchQuery(JNIEnv* env,
 }
 
 base::android::ScopedJavaLocalRef<jstring>
-TemplateUrlServiceAndroid::GetUrlForVoiceSearchQuery(JNIEnv* env,
-                                                     jobject obj,
-                                                     jstring jquery) {
+TemplateUrlServiceAndroid::GetUrlForVoiceSearchQuery(
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj,
+    const JavaParamRef<jstring>& jquery) {
   base::string16 query(base::android::ConvertJavaStringToUTF16(env, jquery));
   std::string url;
 
@@ -188,10 +199,11 @@ TemplateUrlServiceAndroid::GetUrlForVoiceSearchQuery(JNIEnv* env,
 }
 
 base::android::ScopedJavaLocalRef<jstring>
-TemplateUrlServiceAndroid::ReplaceSearchTermsInUrl(JNIEnv* env,
-                                                   jobject obj,
-                                                   jstring jquery,
-                                                   jstring jcurrent_url) {
+TemplateUrlServiceAndroid::ReplaceSearchTermsInUrl(
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj,
+    const JavaParamRef<jstring>& jquery,
+    const JavaParamRef<jstring>& jcurrent_url) {
   TemplateURL* default_provider =
       template_url_service_->GetDefaultSearchProvider();
 
@@ -212,9 +224,9 @@ TemplateUrlServiceAndroid::ReplaceSearchTermsInUrl(JNIEnv* env,
 base::android::ScopedJavaLocalRef<jstring>
 TemplateUrlServiceAndroid::GetUrlForContextualSearchQuery(
     JNIEnv* env,
-    jobject obj,
-    jstring jquery,
-    jstring jalternate_term,
+    const JavaParamRef<jobject>& obj,
+    const JavaParamRef<jstring>& jquery,
+    const JavaParamRef<jstring>& jalternate_term,
     jboolean jshould_prefetch) {
   base::string16 query(base::android::ConvertJavaStringToUTF16(env, jquery));
   std::string url;
@@ -246,7 +258,7 @@ TemplateUrlServiceAndroid::GetUrlForContextualSearchQuery(
 base::android::ScopedJavaLocalRef<jstring>
 TemplateUrlServiceAndroid::GetSearchEngineUrlFromTemplateUrl(
     JNIEnv* env,
-    jobject obj,
+    const JavaParamRef<jobject>& obj,
     jint index) {
   TemplateURL* template_url = template_url_service_->GetTemplateURLs()[index];
   std::string url(template_url->url_ref().ReplaceSearchTerms(
diff --git a/chrome/browser/search_engines/template_url_service_android.h b/chrome/browser/search_engines/template_url_service_android.h
index 091ccd9..0ba635f 100644
--- a/chrome/browser/search_engines/template_url_service_android.h
+++ b/chrome/browser/search_engines/template_url_service_android.h
@@ -21,40 +21,53 @@ class TemplateUrlServiceAndroid : public TemplateURLServiceObserver {
  public:
   TemplateUrlServiceAndroid(JNIEnv* env, jobject obj);
 
-  void Load(JNIEnv* env, jobject obj);
-  void SetUserSelectedDefaultSearchProvider(JNIEnv* env,
-                                            jobject obj,
-                                            jint selected_index);
-  jint GetDefaultSearchProvider(JNIEnv* env, jobject obj);
-  jint GetTemplateUrlCount(JNIEnv* env, jobject obj);
-  jboolean IsLoaded(JNIEnv* env, jobject obj);
-  base::android::ScopedJavaLocalRef<jobject>
-      GetPrepopulatedTemplateUrlAt(JNIEnv* env, jobject obj, jint index);
-  jboolean IsSearchProviderManaged(JNIEnv* env, jobject obj);
-  jboolean IsSearchByImageAvailable(JNIEnv* env, jobject obj);
-  jboolean IsDefaultSearchEngineGoogle(JNIEnv* env, jobject obj);
+  void Load(JNIEnv* env, const base::android::JavaParamRef<jobject>& obj);
+  void SetUserSelectedDefaultSearchProvider(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj,
+      jint selected_index);
+  jint GetDefaultSearchProvider(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj);
+  jint GetTemplateUrlCount(JNIEnv* env,
+                           const base::android::JavaParamRef<jobject>& obj);
+  jboolean IsLoaded(JNIEnv* env,
+                    const base::android::JavaParamRef<jobject>& obj);
+  base::android::ScopedJavaLocalRef<jobject> GetPrepopulatedTemplateUrlAt(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj,
+      jint index);
+  jboolean IsSearchProviderManaged(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj);
+  jboolean IsSearchByImageAvailable(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj);
+  jboolean IsDefaultSearchEngineGoogle(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj);
   base::android::ScopedJavaLocalRef<jstring> GetUrlForSearchQuery(
       JNIEnv* env,
-      jobject obj,
-      jstring jquery);
+      const base::android::JavaParamRef<jobject>& obj,
+      const base::android::JavaParamRef<jstring>& jquery);
   base::android::ScopedJavaLocalRef<jstring> GetUrlForVoiceSearchQuery(
       JNIEnv* env,
-      jobject obj,
-      jstring jquery);
+      const base::android::JavaParamRef<jobject>& obj,
+      const base::android::JavaParamRef<jstring>& jquery);
   base::android::ScopedJavaLocalRef<jstring> ReplaceSearchTermsInUrl(
       JNIEnv* env,
-      jobject obj,
-      jstring jquery,
-      jstring jcurrent_url);
+      const base::android::JavaParamRef<jobject>& obj,
+      const base::android::JavaParamRef<jstring>& jquery,
+      const base::android::JavaParamRef<jstring>& jcurrent_url);
   base::android::ScopedJavaLocalRef<jstring> GetUrlForContextualSearchQuery(
       JNIEnv* env,
-      jobject obj,
-      jstring jquery,
-      jstring jalternate_term,
+      const base::android::JavaParamRef<jobject>& obj,
+      const base::android::JavaParamRef<jstring>& jquery,
+      const base::android::JavaParamRef<jstring>& jalternate_term,
       jboolean jshould_prefetch);
   base::android::ScopedJavaLocalRef<jstring> GetSearchEngineUrlFromTemplateUrl(
       JNIEnv* env,
-      jobject obj,
+      const base::android::JavaParamRef<jobject>& obj,
       jint index);
 
   static bool Register(JNIEnv* env);
diff --git a/chrome/browser/speech/tts_android.cc b/chrome/browser/speech/tts_android.cc
index e8ec307..3d22831 100644
--- a/chrome/browser/speech/tts_android.cc
+++ b/chrome/browser/speech/tts_android.cc
@@ -100,23 +100,27 @@ void TtsPlatformImplAndroid::GetVoices(
   }
 }
 
-void TtsPlatformImplAndroid::VoicesChanged(JNIEnv* env, jobject obj) {
+void TtsPlatformImplAndroid::VoicesChanged(JNIEnv* env,
+                                           const JavaParamRef<jobject>& obj) {
   TtsController::GetInstance()->VoicesChanged();
 }
 
-void TtsPlatformImplAndroid::OnEndEvent(
-    JNIEnv* env, jobject obj, jint utterance_id) {
+void TtsPlatformImplAndroid::OnEndEvent(JNIEnv* env,
+                                        const JavaParamRef<jobject>& obj,
+                                        jint utterance_id) {
   SendFinalTtsEvent(utterance_id, TTS_EVENT_END,
                     static_cast<int>(utterance_.size()));
 }
 
-void TtsPlatformImplAndroid::OnErrorEvent(
-    JNIEnv* env, jobject obj, jint utterance_id) {
+void TtsPlatformImplAndroid::OnErrorEvent(JNIEnv* env,
+                                          const JavaParamRef<jobject>& obj,
+                                          jint utterance_id) {
   SendFinalTtsEvent(utterance_id, TTS_EVENT_ERROR, 0);
 }
 
-void TtsPlatformImplAndroid::OnStartEvent(
-    JNIEnv* env, jobject obj, jint utterance_id) {
+void TtsPlatformImplAndroid::OnStartEvent(JNIEnv* env,
+                                          const JavaParamRef<jobject>& obj,
+                                          jint utterance_id) {
   if (utterance_id != utterance_id_)
     return;
 
diff --git a/chrome/browser/speech/tts_android.h b/chrome/browser/speech/tts_android.h
index f38d674..19ef66d 100644
--- a/chrome/browser/speech/tts_android.h
+++ b/chrome/browser/speech/tts_android.h
@@ -26,10 +26,17 @@ class TtsPlatformImplAndroid : public TtsPlatformImpl {
   void GetVoices(std::vector<VoiceData>* out_voices) override;
 
   // Methods called from Java via JNI.
-  void VoicesChanged(JNIEnv* env, jobject obj);
-  void OnEndEvent(JNIEnv* env, jobject obj, jint utterance_id);
-  void OnErrorEvent(JNIEnv* env, jobject obj, jint utterance_id);
-  void OnStartEvent(JNIEnv* env, jobject obj, jint utterance_id);
+  void VoicesChanged(JNIEnv* env,
+                     const base::android::JavaParamRef<jobject>& obj);
+  void OnEndEvent(JNIEnv* env,
+                  const base::android::JavaParamRef<jobject>& obj,
+                  jint utterance_id);
+  void OnErrorEvent(JNIEnv* env,
+                    const base::android::JavaParamRef<jobject>& obj,
+                    jint utterance_id);
+  void OnStartEvent(JNIEnv* env,
+                    const base::android::JavaParamRef<jobject>& obj,
+                    jint utterance_id);
 
   // Static functions.
   static TtsPlatformImplAndroid* GetInstance();
diff --git a/chrome/browser/spellchecker/spellchecker_session_bridge_android.cc b/chrome/browser/spellchecker/spellchecker_session_bridge_android.cc
index cf02f8c..c10fedf 100644
--- a/chrome/browser/spellchecker/spellchecker_session_bridge_android.cc
+++ b/chrome/browser/spellchecker/spellchecker_session_bridge_android.cc
@@ -62,9 +62,9 @@ void SpellCheckerSessionBridge::RequestTextCheck(int route_id,
 
 void SpellCheckerSessionBridge::ProcessSpellCheckResults(
     JNIEnv* env,
-    jobject jobj,
-    jintArray offset_array,
-    jintArray length_array) {
+    const JavaParamRef<jobject>& jobj,
+    const JavaParamRef<jintArray>& offset_array,
+    const JavaParamRef<jintArray>& length_array) {
   std::vector<int> offsets;
   std::vector<int> lengths;
 
diff --git a/chrome/browser/spellchecker/spellchecker_session_bridge_android.h b/chrome/browser/spellchecker/spellchecker_session_bridge_android.h
index 23353bb..6c56fae 100644
--- a/chrome/browser/spellchecker/spellchecker_session_bridge_android.h
+++ b/chrome/browser/spellchecker/spellchecker_session_bridge_android.h
@@ -29,10 +29,11 @@ class SpellCheckerSessionBridge {
 
   // Receives information from Java side about the typos in a given string
   // of text, processes these and sends them to the renderer.
-  void ProcessSpellCheckResults(JNIEnv* env,
-                                jobject jobj,
-                                jintArray offset_array,
-                                jintArray length_array);
+  void ProcessSpellCheckResults(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& jobj,
+      const base::android::JavaParamRef<jintArray>& offset_array,
+      const base::android::JavaParamRef<jintArray>& length_array);
 
   // Sets the handle to the Java SpellCheckerSessionBridge object to null,
   // marking the Java object for garbage collection.