Fix memory leak of PreviewModeClient in PDF

pdf/out_of_process_instance.cc

 // Copyright (c) 2012 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 "pdf/out_of_process_instance.h"
 
 #include <algorithm>  // for min/max()
 #define _USE_MATH_DEFINES  // for M_PI
 #include <cmath>      // for log() and pow()
 #include <math.h>
@@ skipping 764 matching lines @@
   // TODO(raymes): Make this clearer once the in-process plugin is deleted.
   if (engine_->IsProgressiveLoad()) {
     pp::VarDictionary message;
     message.Set(kType, kJSCancelStreamUrlType);
     PostMessage(message);
   }
 }
 
 void OutOfProcessInstance::DidOpenPreview(int32_t result) {
   if (result == PP_OK) {
-    preview_engine_.reset(PDFEngine::Create(new PreviewModeClient(this)));
+    preview_client_.reset(new PreviewModeClient(this));
+    preview_engine_.reset(PDFEngine::Create(preview_client_.get()));
     preview_engine_->HandleDocumentLoad(embed_preview_loader_);
   } else {
     NOTREACHED();
   }
 }
 
 void OutOfProcessInstance::OnClientTimerFired(int32_t id) {
   engine_->OnCallback(id);
 }
 
@@ skipping 640 matching lines @@
     const pp::FloatPoint& scroll_offset) {
   float max_x = document_size_.width() * zoom_ - plugin_dip_size_.width();
   float x = std::max(std::min(scroll_offset.x(), max_x), 0.0f);
   float min_y = -top_toolbar_height_;
   float max_y = document_size_.height() * zoom_ - plugin_dip_size_.height();
   float y = std::max(std::min(scroll_offset.y(), max_y), min_y);
   return pp::FloatPoint(x, y);
 }
 
 }  // namespace chrome_pdf