Implement screen capture for android

base/android/java/src/org/chromium/base/BaseChromiumApplication.java

Index: base/android/java/src/org/chromium/base/BaseChromiumApplication.java
diff --git a/base/android/java/src/org/chromium/base/BaseChromiumApplication.java b/base/android/java/src/org/chromium/base/BaseChromiumApplication.java
index 2946f6fb0004ad2da54e4e5985f4f75029ff2901..ddef251cfccf19fd91f258d65156f2d1a8e362b3 100644
--- a/base/android/java/src/org/chromium/base/BaseChromiumApplication.java
+++ b/base/android/java/src/org/chromium/base/BaseChromiumApplication.java
@@ -15,6 +15,7 @@ import android.view.Window;
  * Basic application functionality that should be shared among all browser applications.
  */
 public class BaseChromiumApplication extends Application {
+    private Activity mActivity;
     /**
      * Interface to be implemented by listeners for window focus events.
      */
@@ -38,6 +39,7 @@ public class BaseChromiumApplication extends Application {
         registerActivityLifecycleCallbacks(new ActivityLifecycleCallbacks() {
             @Override
             public void onActivityCreated(final Activity activity, Bundle savedInstanceState) {
+                mActivity = activity;
                 Window.Callback callback = activity.getWindow().getCallback();
                 activity.getWindow().setCallback(new WindowCallbackWrapper(callback) {
                     @Override
@@ -113,6 +115,10 @@ public class BaseChromiumApplication extends Application {
     /** Initializes the {@link CommandLine}. */
     public void initCommandLine() {}
 
+    public Activity getActivity() {
+        return mActivity;
+    }
+
     /**
      * This must only be called for contexts whose application is a subclass of
      * {@link BaseChromiumApplication}.