Add an interface to gather text surrounding the selection.

content/browser/android/content_view_core_impl.cc

Index: content/browser/android/content_view_core_impl.cc
diff --git a/content/browser/android/content_view_core_impl.cc b/content/browser/android/content_view_core_impl.cc
index 2335d0a5fb05b9ca4df9420b4bb70bf60b3a5609..4bb56aae1985baf38f5de2f903477838ca0ecdc2 100644
--- a/content/browser/android/content_view_core_impl.cc
+++ b/content/browser/android/content_view_core_impl.cc
@@ -37,6 +37,7 @@
 #include "content/browser/screen_orientation/screen_orientation_dispatcher_host.h"
 #include "content/browser/ssl/ssl_host_state.h"
 #include "content/browser/web_contents/web_contents_view_android.h"
+#include "content/common/frame_messages.h"
 #include "content/common/input/web_input_event_traits.h"
 #include "content/common/input_messages.h"
 #include "content/common/view_messages.h"
@@ -1572,6 +1573,23 @@ void ContentViewCoreImpl::SetBackgroundOpaque(JNIEnv* env, jobject jobj,
     GetRenderWidgetHostViewAndroid()->SetBackgroundOpaque(opaque);
 }
 
+void ContentViewCoreImpl::RequestTextSurroundingSelection(
+    int max_length,
+    const base::Callback<
+        void(const base::string16& content, int start_offset, int end_offset)>&
+        callback) {
+  DCHECK(!callback.is_null());
+  RenderFrameHost* focused_frame = web_contents_->GetFocusedFrame();
+  if (!focused_frame)
+    return;
+  if (GetRenderWidgetHostViewAndroid()) {
+    GetRenderWidgetHostViewAndroid()->SetTextSurroundingSelectionCallback(
+        callback);
+    focused_frame->Send(new FrameMsg_TextSurroundingSelectionRequest(
+        focused_frame->GetRoutingID(), max_length));
+  }
+}
+
 void ContentViewCoreImpl::OnSmartClipDataExtracted(
     const base::string16& result) {
   JNIEnv* env = AttachCurrentThread();