Revert "Create Browser::FromWebContents."

This reverts commit 06b45622.

There already was a function to do this.

BUG=none

Change-Id: I66da553ce7eaecae8945cc1290d8045ff454209b
Reviewed-on: https://chromium-review.googlesource.com/681847Reviewed-by: John Abd-El-Malek <jam@chromium.org>
Commit-Queue: Avi Drissman <avi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#504163}

chrome/browser/prerender/prerender_browsertest.cc

@@ -469,9 +469,8 @@ class NewTabNavigationOrSwapObserver {
     if (swap_observer_)
       return true;
     WebContents* new_tab = content::Details<WebContents>(details).ptr();
-    // Get the TabStripModel. Assume this is attached to a Browser.
     TabStripModel* tab_strip_model =
-        Browser::FromWebContents(new_tab)->tab_strip_model();
+        chrome::FindBrowserWithWebContents(new_tab)->tab_strip_model();
     swap_observer_.reset(new NavigationOrSwapObserver(tab_strip_model,
                                                       new_tab));
     swap_observer_->set_did_start_loading();

chrome/browser/ui/browser.cc

@@ -281,19 +281,6 @@ const extensions::Extension* GetExtensionForOrigin(
 #endif
 }
 
-// Stores a pointer to the Browser in the WebContents.
-struct BrowserLink : public base::SupportsUserData::Data {
-  static const char kKey[];
-
-  explicit BrowserLink(Browser* browser) : browser(browser) {}
-  ~BrowserLink() override = default;
-
-  Browser* browser;
-};
-
-// static
-const char BrowserLink::kKey[] = "BrowserLink";
-
 }  // namespace
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -587,13 +574,6 @@ Browser::~Browser() {
     select_file_dialog_->ListenerDestroyed();
 }
 
-// static
-Browser* Browser::FromWebContents(content::WebContents* web_contents) {
-  const BrowserLink* link =
-      static_cast<BrowserLink*>(web_contents->GetUserData(&BrowserLink::kKey));
-  return link ? link->browser : nullptr;
-}
-
 ///////////////////////////////////////////////////////////////////////////////
 // Getters & Setters
 
@@ -2381,14 +2361,6 @@ void Browser::SetAsDelegate(WebContents* web_contents, bool set_delegate) {
     zoom::ZoomController::FromWebContents(web_contents)->RemoveObserver(this);
     content_translate_driver.RemoveObserver(this);
   }
-
-  // Update the back-link from the WebContents to Browser.
-  if (set_delegate) {
-    web_contents->SetUserData(BrowserLink::kKey,
-                              base::MakeUnique<BrowserLink>(this));
-  } else {
-    web_contents->RemoveUserData(BrowserLink::kKey);
-  }
 }
 
 void Browser::CloseFrame() {

chrome/browser/ui/browser.h

@@ -219,10 +219,6 @@ class Browser : public TabStripModelObserver,
   explicit Browser(const CreateParams& params);
   ~Browser() override;
 
-  // Returns the Browser that contains the specified WebContents. May return
-  // null if no Browser has that WebContents as a tab.
-  static Browser* FromWebContents(content::WebContents* web_contents);
-
   // Set overrides for the initial window bounds and maximized state.
   void set_override_bounds(const gfx::Rect& bounds) {
     override_bounds_ = bounds;