RenderFrameHostDelegate: Fix documentation.

Update the documentation of RenderFrame{Created,Deleted}

The comments said it was about the creation/deletion of RenderFrameHost,
but in reality, it is about its RenderFrame. This is different.

Bug: 609963
Change-Id: Id83af9e82e7d544e68759dff2ffcefabb62c3374
Reviewed-on: https://chromium-review.googlesource.com/c/1286143
Commit-Queue: Arthur Sonzogni <arthursonzogni@chromium.org>
Reviewed-by: Alex Moshchuk <alexmos@chromium.org>
Cr-Commit-Position: refs/heads/master@{#600720}

content/browser/frame_host/render_frame_host_delegate.h

@@ -115,10 +115,14 @@ class CONTENT_EXPORT RenderFrameHostDelegate {
                                       int32_t line_no,
                                       const base::string16& source_id);
 
-  // Informs the delegate whenever a RenderFrameHost is created.
+  // Called when a RenderFrame for |render_frame_host| is created in the
+  // renderer process. Use |RenderFrameDeleted| to listen for when this
+  // RenderFrame goes away.
   virtual void RenderFrameCreated(RenderFrameHost* render_frame_host) {}
 
-  // Informs the delegate whenever a RenderFrameHost is deleted.
+  // Called when a RenderFrame for |render_frame_host| is deleted or the
+  // renderer process in which it runs it has died. Use |RenderFrameCreated| to
+  // listen for when RenderFrame objects are created.
   virtual void RenderFrameDeleted(RenderFrameHost* render_frame_host) {}
 
   // A context menu should be shown, to be built using the context information