[Checkstyle] Fix misc style issues in Java files.

components/gcm_driver/android/java/src/org/chromium/components/gcm_driver/GCMDriver.java

Index: components/gcm_driver/android/java/src/org/chromium/components/gcm_driver/GCMDriver.java
diff --git a/components/gcm_driver/android/java/src/org/chromium/components/gcm_driver/GCMDriver.java b/components/gcm_driver/android/java/src/org/chromium/components/gcm_driver/GCMDriver.java
index f6596eedf6bc7b259df96269ab0c8240ea1a2b56..e13ae1f940954907adddc9595c8aa0c61aaa3028 100644
--- a/components/gcm_driver/android/java/src/org/chromium/components/gcm_driver/GCMDriver.java
+++ b/components/gcm_driver/android/java/src/org/chromium/components/gcm_driver/GCMDriver.java
@@ -162,8 +162,8 @@ public class GCMDriver {
     }
 
     static void onMessageReceived(Context context, final String appId, final Bundle extras) {
-        final String PUSH_API_DATA_KEY = "data";
-        if (!extras.containsKey(PUSH_API_DATA_KEY)) {
+        final String pushApiDataKey = "data";
+        if (!extras.containsKey(pushApiDataKey)) {
             // For now on Android only the Push API uses GCMDriver. To avoid double-handling of
             // messages already handled in Java by other implementations of MultiplexingGcmListener,
             // and unnecessarily waking up the browser processes for all existing GCM messages that
@@ -181,18 +181,18 @@ public class GCMDriver {
         ThreadUtils.assertOnUiThread();
         launchNativeThen(context, new Runnable() {
             @Override public void run() {
-                final String BUNDLE_SENDER_ID = "from";
-                final String BUNDLE_COLLAPSE_KEY = "collapse_key";
-                final String BUNDLE_GCMMPLEX = "com.google.ipc.invalidation.gcmmplex.";
+                final String bundleSenderId = "from";
+                final String bundleCollapseKey = "collapse_key";
+                final String bundleGcmplex = "com.google.ipc.invalidation.gcmmplex.";
 
-                String senderId = extras.getString(BUNDLE_SENDER_ID);
-                String collapseKey = extras.getString(BUNDLE_COLLAPSE_KEY);
+                String senderId = extras.getString(bundleSenderId);
+                String collapseKey = extras.getString(bundleCollapseKey);
 
                 List<String> dataKeysAndValues = new ArrayList<String>();
                 for (String key : extras.keySet()) {
                     // TODO(johnme): Check there aren't other keys that we need to exclude.
-                    if (key == BUNDLE_SENDER_ID || key == BUNDLE_COLLAPSE_KEY ||
-                            key.startsWith(BUNDLE_GCMMPLEX))
+                    if (key == bundleSenderId || key == bundleCollapseKey ||
+                            key.startsWith(bundleGcmplex))
                         continue;
                     dataKeysAndValues.add(key);
                     dataKeysAndValues.add(extras.getString(key));