Fix a crash in pdf::PepperPDFHost::OnHostMsgHasUnsupportedFeature().

components/pdf/renderer/pepper_pdf_host.cc

Index: components/pdf/renderer/pepper_pdf_host.cc
diff --git a/components/pdf/renderer/pepper_pdf_host.cc b/components/pdf/renderer/pepper_pdf_host.cc
index 1355141c2d4d5d9ddd74f6b9b75537f809b2c1cb..962b5dfb384bb0fa57e5ed82da5457231fc2c1d1 100644
--- a/components/pdf/renderer/pepper_pdf_host.cc
+++ b/components/pdf/renderer/pepper_pdf_host.cc
@@ -100,7 +100,12 @@ int32_t PepperPDFHost::OnHostMsgDidStartLoading(
       host_->GetPluginInstance(pp_instance());
   if (!instance)
     return PP_ERROR_FAILED;
-  instance->GetRenderView()->DidStartLoading();
+
+  content::RenderView* render_view = instance->GetRenderView();
+  if (!render_view)
+    return PP_ERROR_FAILED;
+
+  render_view->DidStartLoading();

[tommycli, 2016/07/22 21:47:37]

Since this pattern is now repeated in many methods, can we make a helper
function that looks like GetRenderView() which returns nullptr if either
instance or instance->GetRenderView is null?

[Lei Zhang, 2016/07/22 22:20:21]

Done.

   return PP_OK;
 }
 
@@ -110,7 +115,12 @@ int32_t PepperPDFHost::OnHostMsgDidStopLoading(
       host_->GetPluginInstance(pp_instance());
   if (!instance)
     return PP_ERROR_FAILED;
-  instance->GetRenderView()->DidStopLoading();
+
+  content::RenderView* render_view = instance->GetRenderView();
+  if (!render_view)
+    return PP_ERROR_FAILED;
+
+  render_view->DidStopLoading();
   return PP_OK;
 }
 
@@ -121,8 +131,13 @@ int32_t PepperPDFHost::OnHostMsgSetContentRestriction(
       host_->GetPluginInstance(pp_instance());
   if (!instance)
     return PP_ERROR_FAILED;
-  instance->GetRenderView()->Send(new PDFHostMsg_PDFUpdateContentRestrictions(
-      instance->GetRenderView()->GetRoutingID(), restrictions));
+
+  content::RenderView* render_view = instance->GetRenderView();
+  if (!render_view)
+    return PP_ERROR_FAILED;
+
+  render_view->Send(new PDFHostMsg_PDFUpdateContentRestrictions(
+      render_view->GetRoutingID(), restrictions));
   return PP_OK;
 }
 
@@ -142,14 +157,10 @@ int32_t PepperPDFHost::OnHostMsgHasUnsupportedFeature(
   if (!instance)
     return PP_ERROR_FAILED;
 
-  // TODO(thestig): Turn CHECKs into the proper if statement after figuring out
-  // what's wrong for https://crbug.com/627814
-  CHECK(instance->GetContainer());
-  CHECK(instance->GetContainer()->document().frame());
-  CHECK(instance->GetContainer()->document().frame()->view());
-  blink::WebView* view =
-      instance->GetContainer()->document().frame()->view();
-  content::RenderView* render_view = content::RenderView::FromWebView(view);
+  content::RenderView* render_view = instance->GetRenderView();
+  if (!render_view)
+    return PP_ERROR_FAILED;
+
   render_view->Send(
       new PDFHostMsg_PDFHasUnsupportedFeature(render_view->GetRoutingID()));
   return PP_OK;
@@ -166,8 +177,12 @@ int32_t PepperPDFHost::OnHostMsgSaveAs(
       host_->GetPluginInstance(pp_instance());
   if (!instance)
     return PP_ERROR_FAILED;
-  GURL url = instance->GetPluginURL();
+
   content::RenderView* render_view = instance->GetRenderView();
+  if (!render_view)
+    return PP_ERROR_FAILED;
+
+  GURL url = instance->GetPluginURL();
   content::Referrer referrer;
   referrer.url = url;
   referrer.policy = blink::WebReferrerPolicyDefault;