Revert 220417 "[temporary M30 fix] Disable dragging tabs with we..."

Reverting per the original change description.

> [temporary M30 fix] Disable dragging tabs with web contents modal dialogs displayed
> 
> The full fix for the crashes in the associated bugs in trunk is too
> risky to merge into M30. After discussions among kareng and sky, the
> best approach was to disable dragging of tabs while a web contents modal
> dialog is displayed, to prevent the crashes. This only affects Chrome
> OS and will be reverted after testing in Canary and merging to the
> branch.
> 
> BUG=275274, 274856
> R=sky@chromium.org
> 
> Review URL: https://codereview.chromium.org/23698003

TBR=wittman@chromium.org
BUG=281831

Review URL: https://codereview.chromium.org/23814008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@221834 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/ui/views/tabs/browser_tab_strip_controller.cc

@@ -26,7 +26,6 @@
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/common/url_constants.h"
-#include "components/web_modal/web_contents_modal_dialog_manager.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/user_metrics.h"
 #include "content/public/browser/web_contents.h"
@@ -39,7 +38,6 @@
 
 using content::UserMetricsAction;
 using content::WebContents;
-using web_modal::WebContentsModalDialogManager;
 
 namespace {
 
@@ -366,15 +364,6 @@ void BrowserTabStripController::LayoutTypeMaybeChanged() {
       static_cast<int>(tabstrip_->layout_type()));
 }
 
-bool BrowserTabStripController::IsTabShowingWebViewModalDialog(int index) {
-  DCHECK(model_->ContainsIndex(index));
-  WebContentsModalDialogManager* contents_modal_dialog_manager =
-      WebContentsModalDialogManager::FromWebContents(
-          model_->GetWebContentsAt(index));
-  return contents_modal_dialog_manager &&
-      contents_modal_dialog_manager->IsShowingDialog();
-}
-
 void BrowserTabStripController::OnStartedDraggingTabs() {
   BrowserView* browser_view = BrowserView::GetBrowserViewForBrowser(browser_);
   if (browser_view && !immersive_reveal_lock_.get()) {

chrome/browser/ui/views/tabs/browser_tab_strip_controller.h

@@ -71,7 +71,6 @@ class BrowserTabStripController : public TabStripController,
   virtual void CreateNewTab() OVERRIDE;
   virtual bool IsIncognito() OVERRIDE;
   virtual void LayoutTypeMaybeChanged() OVERRIDE;
-  virtual bool IsTabShowingWebViewModalDialog(int index) OVERRIDE;
   virtual void OnStartedDraggingTabs() OVERRIDE;
   virtual void OnStoppedDraggingTabs() OVERRIDE;
 

chrome/browser/ui/views/tabs/fake_base_tab_strip_controller.cc

@@ -115,10 +115,6 @@ bool FakeBaseTabStripController::IsIncognito() {
 void FakeBaseTabStripController::LayoutTypeMaybeChanged() {
 }
 
-bool FakeBaseTabStripController::IsTabShowingWebViewModalDialog(int index) {
-  return false;
-}
-
 void FakeBaseTabStripController::OnStartedDraggingTabs() {
 }
 

chrome/browser/ui/views/tabs/fake_base_tab_strip_controller.h

@@ -48,7 +48,6 @@ class FakeBaseTabStripController : public TabStripController {
   virtual void CreateNewTab() OVERRIDE;
   virtual bool IsIncognito() OVERRIDE;
   virtual void LayoutTypeMaybeChanged() OVERRIDE;
-  virtual bool IsTabShowingWebViewModalDialog(int index) OVERRIDE;
   virtual void OnStartedDraggingTabs() OVERRIDE;
   virtual void OnStoppedDraggingTabs() OVERRIDE;
 

chrome/browser/ui/views/tabs/tab_strip.cc

@@ -1127,16 +1127,6 @@ void TabStrip::MaybeStartDrag(
       gfx::Screen::GetScreenFor(widget->GetNativeView())->GetNumDisplays() == 1)
     detach_behavior = TabDragController::NOT_DETACHABLE;
 
-#if defined(OS_CHROMEOS)
-  // TODO(wittman): This is a temporary workaround to avoid crbug.com/275274 and
-  // crbug.com/274856 in M30 and should be reverted after merge, as we have a
-  // solution to these bugs in trunk.
-  //
-  // Don't allow detaching if the tab has a WebContentsModalDialogView opened.
-  if (controller()->IsTabShowingWebViewModalDialog(GetModelIndexOfTab(tab)))
-    detach_behavior = TabDragController::NOT_DETACHABLE;
-#endif
-
 #if defined(OS_WIN)
   // It doesn't make sense to drag tabs out on Win8's single window Metro mode.
   if (win8::IsSingleWindowMetroMode())

chrome/browser/ui/views/tabs/tab_strip_controller.h

@@ -99,10 +99,6 @@ class TabStripController {
   // Invoked if the layout type might have changed.
   virtual void LayoutTypeMaybeChanged() = 0;
 
-  // Returns true if the tab at the given index is showing a web view modal
-  // dialog.
-  virtual bool IsTabShowingWebViewModalDialog(int index) = 0;
-
   // Notifies controller that the user started dragging this tabstrip's tabs.
   virtual void OnStartedDraggingTabs() = 0;