Enable PDF accessibility when RenderFrame's accessibility mode changes.

components/pdf/renderer/pepper_pdf_host.cc

 // Copyright 2014 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 "components/pdf/renderer/pepper_pdf_host.h"
 
 #include "components/pdf/common/pdf_messages.h"
 #include "components/pdf/renderer/pdf_accessibility_tree.h"
 #include "content/public/common/referrer.h"
 #include "content/public/renderer/pepper_plugin_instance.h"
@@ skipping 219 matching lines @@
   CreatePdfAccessibilityTreeIfNeeded(instance);
   pdf_accessibility_tree_->SetAccessibilityPageInfo(
       page_info, text_run_info, chars);
   return PP_OK;
 }
 
 void PepperPDFHost::CreatePdfAccessibilityTreeIfNeeded(
     content::PepperPluginInstance* instance) {
   if (!pdf_accessibility_tree_) {
     pdf_accessibility_tree_.reset(
-        new PdfAccessibilityTree(instance->GetRenderView()));
+        new PdfAccessibilityTree(instance->GetRenderFrame()));

[raymes, 2016/07/12 01:36:23]

There's already a function in RendererPpapiHost (host_) to get the RenderFrame.
I also /believe/ that the RenderFrame can be destroyed before this object, so we
shouldn't rely on the pointer being valid. Instead we should call
GetRenderFrameForInstance and cehck the result each time we need to use it.,

[dmazzoni, 2016/07/13 23:17:53]

Got it.

OK, now I'm passing RendererPpapiHost and PP_Instance to the
PdfAccessibilityTree constructor, that should resolve any
potential lifetime issues.

   }
 }
 
 }  // namespace pdf