[TTS] Cleanup a potential issue introduced in CL 2157793002

chrome/browser/android/contextualsearch/contextual_search_delegate.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/android/contextualsearch/contextual_search_delegate.h"
 
 #include <algorithm>
 
 #include "base/base64.h"
 #include "base/command_line.h"
@@ skipping 230 matching lines @@
   }
   return request;
 }
 
 void ContextualSearchDelegate::GatherSurroundingTextWithCallback(
     const std::string& selection,
     bool use_resolved_search_term,
     content::WebContents* web_contents,
     bool may_send_base_page_url,
     HandleSurroundingsCallback callback) {
-  DCHECK(web_contents);
-  DCHECK(!callback.is_null());
-  DCHECK(!selection.empty());
-  RenderFrameHost* focused_frame = web_contents->GetFocusedFrame();
-  if (!focused_frame) {
-    callback.Run(base::string16(), 0, 0);
-    return;
-  }
   // Immediately cancel any request that's in flight, since we're building a new
   // context (and the response disposes of any existing context).
   search_term_fetcher_.reset();
   BuildContext(selection, use_resolved_search_term, web_contents,
                may_send_base_page_url);
-  focused_frame->RequestTextSurroundingSelection(
-      callback, field_trial_->GetSurroundingSize());
+  DCHECK(web_contents);
+  RenderFrameHost* focused_frame = web_contents->GetFocusedFrame();
+  if (focused_frame) {
+    focused_frame->RequestTextSurroundingSelection(
+        callback, field_trial_->GetSurroundingSize());
+  } else {
+    callback.Run(base::string16(), 0, 0);
+  }
 }
 
 void ContextualSearchDelegate::BuildContext(
     const std::string& selection,
     bool use_resolved_search_term,
     content::WebContents* web_contents,
     bool may_send_base_page_url) {
   // Decide if the URL should be sent with the context.
   GURL page_url(web_contents->GetURL());
   GURL url_to_send;
@@ skipping 263 matching lines @@
     end_offset -= trim;
   }
   if (result_text.length() > end_offset + padding_each_side_pinned) {
     // Trim the end.
     result_text = result_text.substr(0, end_offset + padding_each_side_pinned);
   }
   *start = start_offset;
   *end = end_offset;
   return result_text;
 }