Refactor context#getApplicationContext calls from remoting

In preparation for enabling an errorprone check that would prohibit
context#getApplicationContext in favour of ContextUtils#getApplicationContext
see https://bugs.chromium.org/p/chromium/issues/detail?id=560466
for context.

Bug: 846456
Change-Id: I13c432d238876cdf8c075e28f74d49e86f8f00a8
Reviewed-on: https://chromium-review.googlesource.com/c/1340376Reviewed-by: Lambros Lambrou <lambroslambrou@chromium.org>
Commit-Queue: Aiden Benner <abenner@google.com>
Cr-Commit-Position: refs/heads/master@{#608904}

remoting/android/java/src/org/chromium/chromoting/ChromotingDownloadManager.java

@@ -15,6 +15,8 @@ import android.database.Cursor;
 import android.net.Uri;
 import android.os.Environment;
 
+import org.chromium.base.ContextUtils;
+
 import java.io.File;
 import java.util.HashSet;
 import java.util.Set;
@@ -67,7 +69,7 @@ public class ChromotingDownloadManager {
             if (needToBeDownloaded(i)) {
                 DownloadManager.Request request =
                         new DownloadManager.Request(Uri.parse(mUris[i]));
-                request.setDestinationInExternalFilesDir(mActivity.getApplicationContext(),
+                request.setDestinationInExternalFilesDir(ContextUtils.getApplicationContext(),
                         Environment.DIRECTORY_DOWNLOADS, mNames[i]);
                 mUnfinishedDownloadIds.add(mDownloadManager.enqueue(request));
             }

remoting/android/java/src/org/chromium/chromoting/ThirdPartyTokenFetcher.java

@@ -14,6 +14,7 @@ import android.net.Uri;
 import android.text.TextUtils;
 import android.util.Base64;
 
+import org.chromium.base.ContextUtils;
 import org.chromium.base.Log;
 import org.chromium.base.SecureRandomInitializer;
 
@@ -87,7 +88,7 @@ public class ThirdPartyTokenFetcher {
         this.mCallback = callback;
         this.mTokenUrlPatterns = tokenUrlPatterns;
 
-        this.mRedirectUriScheme = context.getApplicationContext().getPackageName();
+        this.mRedirectUriScheme = ContextUtils.getApplicationContext().getPackageName();
 
         // We don't follow the OAuth spec (http://tools.ietf.org/html/rfc6749#section-3.1.2) of the
         // redirect URI as it is possible for the other applications to intercept the redirect URI.
@@ -230,8 +231,7 @@ public class ThirdPartyTokenFetcher {
         public static void setEnabled(Activity context, boolean enabled) {
             int enabledState = enabled ? PackageManager.COMPONENT_ENABLED_STATE_ENABLED
                                        : PackageManager.COMPONENT_ENABLED_STATE_DEFAULT;
-            ComponentName component = new ComponentName(
-                    context.getApplicationContext(),
+            ComponentName component = new ComponentName(ContextUtils.getApplicationContext(),
                     ThirdPartyTokenFetcher.OAuthRedirectActivity.class);
             context.getPackageManager().setComponentEnabledSetting(
                     component,

remoting/android/java/src/org/chromium/chromoting/jni/JniInterface.java

@@ -24,9 +24,9 @@ public class JniInterface {
      * code. Called on the UI thread.
      * @param context The Application context.
      */
+    @SuppressWarnings("NoContextGetApplicationContext")
     public static void loadLibrary(Context context) {
         ContextUtils.initApplicationContext(context.getApplicationContext());
-        JniOAuthTokenGetter.setContext(context);
         try {
             System.loadLibrary(LIBRARY_NAME);
         } catch (UnsatisfiedLinkError e) {

remoting/android/java/src/org/chromium/chromoting/jni/JniOAuthTokenGetter.java

@@ -4,9 +4,7 @@
 
 package org.chromium.chromoting.jni;
 
-import android.annotation.SuppressLint;
-import android.content.Context;
-
+import org.chromium.base.ContextUtils;
 import org.chromium.base.Log;
 import org.chromium.base.annotations.CalledByNative;
 import org.chromium.base.annotations.JNINamespace;
@@ -25,18 +23,9 @@ public class JniOAuthTokenGetter {
     private static final String TAG = "Chromoting";
     private static final String TOKEN_SCOPE = "oauth2:https://www.googleapis.com/auth/chromoting";
 
-    @SuppressLint("StaticFieldLeak")
-    private static Context sContext;
     private static String sAccount;
     private static String sLatestToken;
 
-    public static void setContext(Context context) {
-        Preconditions.notNull(context);
-        // Always store the application context so that we don't leak the activity context by
-        // accident.
-        sContext = context.getApplicationContext();
-    }
-
     public static void setAccount(String account) {
         Preconditions.notNull(account);
         sAccount = account;
@@ -44,36 +33,38 @@ public class JniOAuthTokenGetter {
 
     @CalledByNative
     private static void fetchAuthToken(long callbackPtr) {
-        Preconditions.notNull(sContext);
+        Preconditions.notNull(ContextUtils.getApplicationContext());
         Preconditions.notNull(sAccount);
-        new OAuthTokenFetcher(sContext, sAccount, TOKEN_SCOPE, new Callback() {
-            @Override
-            public void onTokenFetched(String token) {
-                sLatestToken = token;
-                nativeResolveOAuthTokenCallback(
-                        callbackPtr, OAuthTokenStatus.SUCCESS, sAccount, token);
-            }
+        new OAuthTokenFetcher(ContextUtils.getApplicationContext(), sAccount, TOKEN_SCOPE,
+                new Callback() {
+                    @Override
+                    public void onTokenFetched(String token) {
+                        sLatestToken = token;
+                        nativeResolveOAuthTokenCallback(
+                                callbackPtr, OAuthTokenStatus.SUCCESS, sAccount, token);
+                    }
 
-            @Override
-            public void onError(Error error) {
-                Log.e(TAG, "Failed to fetch token. Error: ", error);
-                int status;
-                switch (error) {
-                    case NETWORK:
-                        status = OAuthTokenStatus.NETWORK_ERROR;
-                        break;
-                    case UI:
-                    case UNEXPECTED:
-                    case INTERRUPTED:
-                        status = OAuthTokenStatus.AUTH_ERROR;
-                        break;
-                    default:
-                        assert false : "Unreached";
-                        status = -1;
-                }
-                nativeResolveOAuthTokenCallback(callbackPtr, status, null, null);
-            }
-        }).fetch();
+                    @Override
+                    public void onError(Error error) {
+                        Log.e(TAG, "Failed to fetch token. Error: ", error);
+                        int status;
+                        switch (error) {
+                            case NETWORK:
+                                status = OAuthTokenStatus.NETWORK_ERROR;
+                                break;
+                            case UI:
+                            case UNEXPECTED:
+                            case INTERRUPTED:
+                                status = OAuthTokenStatus.AUTH_ERROR;
+                                break;
+                            default:
+                                assert false : "Unreached";
+                                status = -1;
+                        }
+                        nativeResolveOAuthTokenCallback(callbackPtr, status, null, null);
+                    }
+                })
+                .fetch();
     }
 
     @CalledByNative
@@ -81,19 +72,21 @@ public class JniOAuthTokenGetter {
         if (sLatestToken == null || sLatestToken.isEmpty()) {
             return;
         }
-        Preconditions.notNull(sContext);
+        Preconditions.notNull(ContextUtils.getApplicationContext());
         Preconditions.notNull(sAccount);
-        new OAuthTokenFetcher(sContext, sAccount, TOKEN_SCOPE, new Callback() {
-            @Override
-            public void onTokenFetched(String token) {
-                sLatestToken = token;
-            }
+        new OAuthTokenFetcher(ContextUtils.getApplicationContext(), sAccount, TOKEN_SCOPE,
+                new Callback() {
+                    @Override
+                    public void onTokenFetched(String token) {
+                        sLatestToken = token;
+                    }
 
-            @Override
-            public void onError(Error error) {
-                Log.e(TAG, "Failed to clear token. Error: ", error);
-            }
-        }).clearAndFetch(sLatestToken);
+                    @Override
+                    public void onError(Error error) {
+                        Log.e(TAG, "Failed to clear token. Error: ", error);
+                    }
+                })
+                .clearAndFetch(sLatestToken);
     }
 
     private static native void nativeResolveOAuthTokenCallback(