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 0fdc058b01df1913bdd2fd047833cf83185792e2..625121e78ec1c556e1fa68810c5bb697a08107af 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"
@@ -222,7 +223,8 @@ ContentViewCoreImpl::ContentViewCoreImpl(
       view_android_(view_android),
       window_android_(window_android),
       device_orientation_(0),
-      accessibility_enabled_(false) {
+      accessibility_enabled_(false),
+      text_surroundings_delegate_(NULL) {
   CHECK(web_contents) <<
       "A ContentViewCoreImpl should be created with a valid WebContents.";
 
@@ -246,7 +248,6 @@ ContentViewCoreImpl::ContentViewCoreImpl(
   java_bridge_dispatcher_host_manager_.reset(
       new JavaBridgeDispatcherHostManager(web_contents,
                                           java_bridge_retained_object_set));
-

[jdduke (slow), 2014/06/17 22:43:26]

Hmm, did you remove this line break? If so, maybe undo to reduce git blame noise
(can't tell if it was from the rebase).

[donnd, 2014/06/18 00:09:58]

Looks like I did -- replaced.

   InitWebContents();
 }
 
@@ -1538,6 +1539,21 @@ void ContentViewCoreImpl::SetAccessibilityEnabledInternal(bool enabled) {
   }
 }
 
+void ContentViewCoreImpl::SetTextSurroundingsDelegate(
+    TextSurroundingsDelegate* delegate) {
+  text_surroundings_delegate_ = delegate;
+}
+
+void ContentViewCoreImpl::OnTextSurroundingSelectionResponse(
+    const base::string16& content,
+    int start_offset,
+    int end_offset) {
+  if (text_surroundings_delegate_ != NULL) {

[jdduke (slow), 2014/06/17 22:43:26]

Nit, no need for "!= NULL", you can just do:

if (text_surroundings_delegate_)

[donnd, 2014/06/18 00:09:58]

Done.

+    text_surroundings_delegate_->OnTextSurroundingSelectionResponse(
+        content, start_offset, end_offset);
+  }
+}
+
 void ContentViewCoreImpl::SendOrientationChangeEventInternal() {
   RenderWidgetHostViewAndroid* rwhv = GetRenderWidgetHostViewAndroid();
   if (rwhv)
@@ -1604,6 +1620,13 @@ void ContentViewCoreImpl::SetBackgroundOpaque(JNIEnv* env, jobject jobj,
     GetRenderWidgetHostViewAndroid()->SetBackgroundOpaque(opaque);
 }
 
+void ContentViewCoreImpl::RequestTextSurroundingSelection(
+    int max_length) const {
+  RenderFrameHost* focused_frame = web_contents_->GetFocusedFrame();

[jdduke (slow), 2014/06/17 22:43:26]

What guarantees do we have that focused_frame will be non-NULL?

[jdduke (slow), 2014/06/17 22:43:26]

Should we enforce that |text_surroundings_delegate_| is non-NULL here (i.e.,
|DCHECK(text_surroundings_delegate_);|)? If it should always be non-NULL for
your use-case let's go ahead and add that so that somebody doesn't come along
and just start using the API without addressing how the response would be
routed.  It's OK not to enforce that condition on the response, as the delegate
may have gone away in the meantime.

[donnd, 2014/06/18 00:09:58]

Good idea to check it.  I'm cribbing off of Mounir's CL here, so I just figured
he'd know, but doesn't hurt to check!  I think he figured there needed to be a
focused frame to have a selection, but maybe this method could be called without
a selection or selected frame.

[donnd, 2014/06/18 00:09:58]

Done.

+  focused_frame->Send(new FrameMsg_TextSurroundingSelectionRequest(
+      focused_frame->GetRoutingID(), max_length));
+}
+
 void ContentViewCoreImpl::OnSmartClipDataExtracted(
     const base::string16& result) {
   JNIEnv* env = AttachCurrentThread();