[Android WebView] Implement the capture picture API.

android_webview/native/aw_contents.h

Index: android_webview/native/aw_contents.h
diff --git a/android_webview/native/aw_contents.h b/android_webview/native/aw_contents.h
index d482465afa9078b63f2ef04a436a01128b3064e8..fbcbb3f29a33a9fb775b85f657277122a082439a 100644
--- a/android_webview/native/aw_contents.h
+++ b/android_webview/native/aw_contents.h
@@ -16,6 +16,8 @@
 #include "base/memory/scoped_ptr.h"
 #include "content/public/browser/android/compositor.h"
 #include "content/public/browser/javascript_dialogs.h"
+#include "skia/ext/refptr.h"
+#include "third_party/skia/include/core/SkPicture.h"
 
 typedef void* EGLContext;
 class TabContents;
@@ -102,6 +104,11 @@ class AwContents : public FindHelper::Listener,
   void SetScrollForHWFrame(JNIEnv* env, jobject obj,
                            int scroll_x, int scroll_y);
   void FocusFirstNode(JNIEnv* env, jobject obj);
+  void CapturePicture(JNIEnv* env, jobject obj, jobject picture_data);
+  void EnableOnNewPicture(JNIEnv* env,
+                          jobject obj,
+                          jboolean enabled,
+                          jboolean invalidation_only);
 
   // Find-in-page API and related methods.
   jint FindAllSync(JNIEnv* env, jobject obj, jstring search_string);
@@ -127,6 +134,10 @@ class AwContents : public FindHelper::Listener,
   // AwRenderViewHostExt::Client implementation.
   virtual void OnPictureUpdated(int process_id, int render_view_id) OVERRIDE;
 
+  // Returns the latest locally available picture if any.
+  // If none is available will synchronously request the latest one.
+  skia::RefPtr<SkPicture> GetLastCapturedPicture();
+
  private:
   void Invalidate();
   void SetWebContents(content::WebContents* web_contents);
@@ -151,6 +162,8 @@ class AwContents : public FindHelper::Listener,
   bool view_visible_;
   bool compositor_visible_;
   bool is_composite_pending_;
+  bool on_new_picture_enabled_;
+  bool on_new_picture_invalidation_only_;
 
   // Used only for detecting Android View System context changes.
   // Not to be used between draw calls.