Browser Plugin: Don't crash browser when reloading crashed webview

We were accessing a NULL RWHV on BrowserPluginGuest::SetFocus. This CL
adds a guard to ensure we only attempt to set focus if we have a View.

BUG=413874

Review URL: https://codereview.chromium.org/564153003

Cr-Commit-Position: refs/heads/master@{#294674}

1 files changed, 6 insertions, 4 deletions

diff --git a/content/browser/browser_plugin/browser_plugin_guest.cc b/content/browser/browser_plugin/browser_plugin_guest.cc
index 569c9de..847eff8 100644
--- a/content/browser/browser_plugin/browser_plugin_guest.cc
+++ b/content/browser/browser_plugin/browser_plugin_guest.cc
@@ -109,13 +109,16 @@ base::WeakPtr<BrowserPluginGuest> BrowserPluginGuest::AsWeakPtr() {
 
 void BrowserPluginGuest::SetFocus(RenderWidgetHost* rwh, bool focused) {
   focused_ = focused;
+  if (!rwh)
+    return;
+
   rwh->Send(new InputMsg_SetFocus(rwh->GetRoutingID(), focused));
   if (!focused && mouse_locked_)
     OnUnlockMouse();
 
   // Restore the last seen state of text input to the view.
   RenderWidgetHostViewBase* rwhv = static_cast<RenderWidgetHostViewBase*>(
-      web_contents()->GetRenderWidgetHostView());
+      rwh->GetView());
   if (rwhv) {
     ViewHostMsg_TextInputState_Params params;
     params.type = last_text_input_type_;
@@ -718,9 +721,8 @@ void BrowserPluginGuest::OnResizeGuest(
 
 void BrowserPluginGuest::OnSetFocus(int browser_plugin_instance_id,
                                     bool focused) {
-
-  RenderWidgetHost* rwh = web_contents()->GetRenderWidgetHostView()->
-      GetRenderWidgetHost();
+  RenderWidgetHostView* rwhv = web_contents()->GetRenderWidgetHostView();
+  RenderWidgetHost* rwh = rwhv ? rwhv->GetRenderWidgetHost() : NULL;
   SetFocus(rwh, focused);
 }