Miscellaneous cleanups from several months ago I never got around to landing.

chrome/browser/printing/background_printing_manager.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/printing/background_printing_manager.h"
 
 #include "chrome/browser/printing/print_job.h"
 #include "chrome/browser/printing/print_preview_tab_controller.h"
 #include "chrome/browser/sessions/restore_tab_helper.h"
 #include "chrome/browser/ui/browser_list.h"
@@ skipping 39 matching lines @@
       chrome::NOTIFICATION_TAB_CONTENTS_DESTROYED, preview_source)) {
     registrar_.Add(this, chrome::NOTIFICATION_TAB_CONTENTS_DESTROYED,
                    preview_source);
   }
 
   // If a tab that is printing crashes, the user cannot destroy it since it is
   // not in any tab strip. Thus listen for crashes here and delete the tab.
   //
   // Multiple sites may share the same RenderProcessHost, so check if this
   // notification has already been added.
-  content::RenderProcessHost* rph =
-      preview_tab->web_contents()->GetRenderProcessHost();
+  content::Source<content::RenderProcessHost> rph_source(
+      preview_tab->web_contents()->GetRenderProcessHost());
   if (!registrar_.IsRegistered(this,
-                               content::NOTIFICATION_RENDERER_PROCESS_CLOSED,
-                               content::Source<content::RenderProcessHost>(
-                                  rph))) {
+      content::NOTIFICATION_RENDERER_PROCESS_CLOSED, rph_source)) {
     registrar_.Add(this, content::NOTIFICATION_RENDERER_PROCESS_CLOSED,
-                   content::Source<content::RenderProcessHost>(rph));
+                   rph_source);
   }
 
   // Activate the initiator tab.
   PrintPreviewTabController* tab_controller =
       PrintPreviewTabController::GetInstance();
   if (!tab_controller)
     return;
   TabContents* initiator_tab = tab_controller->GetInitiatorTab(preview_tab);
   if (!initiator_tab)
     return;
   WebContents* web_contents = initiator_tab->web_contents();
   web_contents->GetDelegate()->ActivateContents(web_contents);
 }
 
 void BackgroundPrintingManager::Observe(
     int type,
     const content::NotificationSource& source,
     const content::NotificationDetails& details) {
-  switch (type) {
-    case content::NOTIFICATION_RENDERER_PROCESS_CLOSED: {
-      OnRendererProcessClosed(
-          content::Source<content::RenderProcessHost>(source).ptr());
-      break;
-    }
-    case chrome::NOTIFICATION_PRINT_JOB_RELEASED: {
-      OnPrintJobReleased(content::Source<TabContents>(source).ptr());
-      break;
-    }
-    case chrome::NOTIFICATION_TAB_CONTENTS_DESTROYED: {
-      OnTabContentsDestroyed(content::Source<TabContents>(source).ptr());
-      break;
-    }
-    default: {
-      NOTREACHED();
-      break;
-    }
+  if (type == content::NOTIFICATION_RENDERER_PROCESS_CLOSED) {
+    OnRendererProcessClosed(
+        content::Source<content::RenderProcessHost>(source).ptr());
+  } else if (type == chrome::NOTIFICATION_PRINT_JOB_RELEASED) {
+    OnPrintJobReleased(content::Source<TabContents>(source).ptr());
+  } else {
+    DCHECK_EQ(chrome::NOTIFICATION_TAB_CONTENTS_DESTROYED, type);
+    OnTabContentsDestroyed(content::Source<TabContents>(source).ptr());
   }
 }
 
 void BackgroundPrintingManager::OnRendererProcessClosed(
     content::RenderProcessHost* rph) {
   TabContentsSet preview_tabs_pending_deletion;
   TabContentsSet::const_iterator it;
   for (it = begin(); it != end(); ++it) {
     TabContents* preview_tab = *it;
     if (preview_tab->web_contents()->GetRenderProcessHost() == rph) {
@@ skipping 79 matching lines @@
 
 bool BackgroundPrintingManager::HasPrintPreviewTab(
     TabContents* preview_tab) {
   if (printing_tabs_.find(preview_tab) != printing_tabs_.end())
     return true;
   return printing_tabs_pending_deletion_.find(preview_tab) !=
       printing_tabs_pending_deletion_.end();
 }
 
 }  // namespace printing