Move GetDocument method from WebFrame to WebLocalFrame.

content/renderer/pepper/pepper_file_system_host.cc

Index: content/renderer/pepper/pepper_file_system_host.cc
diff --git a/content/renderer/pepper/pepper_file_system_host.cc b/content/renderer/pepper/pepper_file_system_host.cc
index 679b3de3da4cbfd92b17a56c7d35ae1b1ff7ab00..894076fd87e4d683ee2320885f92f3a099bbe708 100644
--- a/content/renderer/pepper/pepper_file_system_host.cc
+++ b/content/renderer/pepper/pepper_file_system_host.cc
@@ -20,7 +20,7 @@
 #include "ppapi/shared_impl/file_type_conversion.h"
 #include "storage/common/fileapi/file_system_util.h"
 #include "third_party/WebKit/public/web/WebDocument.h"
-#include "third_party/WebKit/public/web/WebFrame.h"
+#include "third_party/WebKit/public/web/WebLocalFrame.h"
 #include "third_party/WebKit/public/web/WebView.h"
 
 namespace content {
@@ -132,12 +132,13 @@ int32_t PepperFileSystemHost::OnHostMsgInitIsolatedFileSystem(
   if (!view)
     return PP_ERROR_FAILED;
 
-  const GURL& url = view->GetWebView()->MainFrame()->GetDocument().Url();

[alexmos, 2017/06/20 22:44:11]

Wow, this seems like a bug we hadn't noticed before, though it doesn't look like
we observed any crashes for it.  Thanks for fixing it (and the one below)!

+  url::Origin main_frame_origin(
+      view->GetWebView()->MainFrame()->GetSecurityOrigin());
   const std::string root_name = ppapi::IsolatedFileSystemTypeToRootName(type);
   if (root_name.empty())
     return PP_ERROR_BADARGUMENT;
   root_url_ = GURL(storage::GetIsolatedFileSystemRootURIString(
-      url.GetOrigin(), fsid, root_name));
+      main_frame_origin.GetURL(), fsid, root_name));
   opened_ = true;
   return PP_OK;
 }