This is a fix for crash bug crbug:783189

initialize PluginInfoPtrs. The crash happens when chrome::mojom::GetPluginInfo
fails in sync mode. Then the output PluginInfoPtr is left null. We instead
default initialize it with PluginInfo::New() as this is what the subsequent
code expects.

Bug: 783189
Change-Id: I51e25b127858b8ede79f6762f0f5e870166254d1
Reviewed-on: https://chromium-review.googlesource.com/762848Reviewed-by: John Abd-El-Malek <jam@chromium.org>
Reviewed-by: Yuzhu Shen <yzshen@chromium.org>
Reviewed-by: Sam McNally <sammc@chromium.org>
Commit-Queue: Nicholas Verne <nverne@chromium.org>
Cr-Commit-Position: refs/heads/master@{#515873}

chrome/renderer/chrome_content_renderer_client.cc

@@ -678,7 +678,7 @@ bool ChromeContentRendererClient::OverrideCreatePlugin(
 
   GURL url(params.url);
 #if BUILDFLAG(ENABLE_PLUGINS)
-  chrome::mojom::PluginInfoPtr plugin_info;
+  chrome::mojom::PluginInfoPtr plugin_info = chrome::mojom::PluginInfo::New();
   GetPluginInfoHost()->GetPluginInfo(
       render_frame->GetRoutingID(), url,
       render_frame->GetWebFrame()->Top()->GetSecurityOrigin(), orig_mime_type,

chrome/renderer/plugins/chrome_plugin_placeholder.cc

@@ -211,7 +211,7 @@ void ChromePluginPlaceholder::PluginListChanged() {
   if (!render_frame() || !plugin())
     return;
 
-  chrome::mojom::PluginInfoPtr plugin_info;
+  chrome::mojom::PluginInfoPtr plugin_info = chrome::mojom::PluginInfo::New();
   std::string mime_type(GetPluginParams().mime_type.Utf8());
 
   ChromeContentRendererClient::GetPluginInfoHost()->GetPluginInfo(