Remove most content-level dependencies from TranslateManager.

components/translate/content/browser/content_translate_driver.cc

 // Copyright 2014 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 "components/translate/content/browser/content_translate_driver.h"
 
 #include "base/logging.h"
 #include "components/translate/content/common/translate_messages.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/navigation_controller.h"
 #include "content/public/browser/navigation_details.h"
 #include "content/public/browser/navigation_entry.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/web_contents.h"
+#include "url/gurl.h"
 
 ContentTranslateDriver::ContentTranslateDriver(
     content::NavigationController* nav_controller)
     : navigation_controller_(nav_controller),
       language_state_(this),
       observer_(NULL) {
   DCHECK(navigation_controller_);
 }
 
 ContentTranslateDriver::~ContentTranslateDriver() {}
@@ skipping 61 matching lines @@
   }
 
   content::WebContents* web_contents = navigation_controller_->GetWebContents();
   web_contents->GetRenderViewHost()->Send(new ChromeViewMsg_RevertTranslation(
       web_contents->GetRenderViewHost()->GetRoutingID(), entry->GetPageID()));
 }
 
 bool ContentTranslateDriver::IsOffTheRecord() {
   return navigation_controller_->GetBrowserContext()->IsOffTheRecord();
 }
+
+const std::string& ContentTranslateDriver::GetContentsMimeType() {
+  return navigation_controller_->GetWebContents()->GetContentsMimeType();
+}
+
+const GURL& ContentTranslateDriver::GetLastCommittedURL() {
+  return navigation_controller_->GetWebContents()->GetLastCommittedURL();
+}
+
+const GURL& ContentTranslateDriver::GetActiveURL() {
+  content::NavigationEntry* entry = navigation_controller_->GetActiveEntry();

[droger, 2014/04/08 12:01:28]

Not sure if we can do something about it, but GetActiveEntry() is deprecated.
GetVisibleEntry() should be used instead.

I am also not quite sure what is the difference between 
navigation_controller_->GetActiveEntry()->GetURL() and
navigation_controller_->GetWebContents()->GetVisibleURL() (which you use a
couple lines below).

Another source of confusion is that it looks like your API mirrors the
NavigationController API, but the implementation actually does not (one of them
goes through webcontents and not the other one).

That said I don't have any solution to propose unfortunately.

[blundell, 2014/04/08 12:46:02]

The problem is that GetActiveEntry() and GetVisibleEntry() don't have the same
semantics; I'd prefer to avoid changing semantics as part of these refactorings.

The latter call is the same as
navigation_controller_->GetVisibleEntry()->GetURL() just wrapped up to return an
empty GURL if there's no visible entry, which maybe answers your question about
the parallelism to the NavigationController API.

On 2014/04/08 12:01:28, droger wrote:

[droger, 2014/04/08 13:01:21]

Yes it does answer my question. Thanks.

+  if (!entry)
+    return GURL::EmptyGURL();
+  return entry->GetURL();
+}
+
+const GURL& ContentTranslateDriver::GetVisibleURL() {
+  return navigation_controller_->GetWebContents()->GetVisibleURL();
+}
+
+bool ContentTranslateDriver::HasCurrentPage() {
+  return (navigation_controller_->GetActiveEntry() != NULL);
+}
+
+int ContentTranslateDriver::GetCurrentPageID() {
+  DCHECK(HasCurrentPage());
+  content::NavigationEntry* entry = navigation_controller_->GetActiveEntry();
+  return entry->GetPageID();
+}