[Android WebView] Implement the capture picture API.

android_webview/java/src/org/chromium/android_webview/AwContentsClient.java

Index: android_webview/java/src/org/chromium/android_webview/AwContentsClient.java
diff --git a/android_webview/java/src/org/chromium/android_webview/AwContentsClient.java b/android_webview/java/src/org/chromium/android_webview/AwContentsClient.java
index cdaf97c62c981ca28657569ac7ebc6b8490b2656..38514f61443427a01d970b13170a4aeb411b38a3 100644
--- a/android_webview/java/src/org/chromium/android_webview/AwContentsClient.java
+++ b/android_webview/java/src/org/chromium/android_webview/AwContentsClient.java
@@ -37,6 +37,18 @@ public abstract class AwContentsClient extends ContentViewClient {
 
     private AwWebContentsObserver mWebContentsObserver;
 
+    /**
+     * Data required to export a native SkPicture object.
+     */
+    public static class ExternalPictureData {
+        /** Address of the native SkPicture object. Can be null if no picture is provided. */
+        public int nativePicture;
+        /** Width of the native picture, if any. */
+        public int width;
+        /** Height of the native picture, if any. */
+        public int height;
+    }
+
     //--------------------------------------------------------------------------------------------
     //                        Adapter for WebContentsDelegate methods.
     //--------------------------------------------------------------------------------------------
@@ -249,6 +261,12 @@ public abstract class AwContentsClient extends ContentViewClient {
     public abstract void onFindResultReceived(int activeMatchOrdinal, int numberOfMatches,
             boolean isDoneCounting);
 
+    /**
+     * Called whenever there is a new content picture available.
+     * @param externalPicture Object describing the external native picture.
+     */
+    public abstract void onNewPicture(ExternalPictureData externalPicture);
+
     public abstract void onPageStarted(String url);
 
     public abstract void onPageFinished(String url);