android: Migrate old content readback to use async readback (and delegated renderer)

content/public/browser/android/content_view_core.h

Index: content/public/browser/android/content_view_core.h
diff --git a/content/public/browser/android/content_view_core.h b/content/public/browser/android/content_view_core.h
index 85766ee504c6ef347320cd6a4e5957b4280f78ea..1113d79eb71d88037d4eda0258b174cead0e32a0 100644
--- a/content/public/browser/android/content_view_core.h
+++ b/content/public/browser/android/content_view_core.h
@@ -12,6 +12,8 @@
 #include "content/common/content_export.h"
 #include "content/public/browser/navigation_controller.h"
 
+class SkBitmap;
+
 namespace cc {
 class Layer;
 }
@@ -48,9 +50,15 @@ class CONTENT_EXPORT ContentViewCore {
   virtual void LoadUrl(NavigationController::LoadURLParams& params) = 0;
   virtual jint GetCurrentRenderProcessId(JNIEnv* env, jobject obj) = 0;
   virtual void ShowPastePopup(int x, int y) = 0;
-  virtual unsigned int GetScaledContentTexture(
+
+  // Request a scaled content readback.  The result is passed through the
+  // callback.  The boolean parameter indicates whether the readback was a
+  // success or not.  The content is passed through the SkBitmap parameter.
+  // |out_size| is returned with the size of the content.
+  virtual void GetScaledContentBitmap(
       float scale,
-      gfx::Size* out_size) = 0;
+      gfx::Size* out_size,
+      const base::Callback<void(bool, const SkBitmap&)>& result_callback) = 0;
   virtual float GetDpiScale() const = 0;
   virtual void RequestContentClipping(const gfx::Rect& clipping,
                                       const gfx::Size& content_size) = 0;