winaura: Do not create WindowObservers for BrowserPlugin.

content/browser/web_contents/web_contents_view_aura.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 "content/browser/web_contents/web_contents_view_aura.h"
 
 #include "base/auto_reset.h"
 #include "base/command_line.h"
 #include "base/metrics/histogram.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 80 matching lines @@
   return mode == (base::i18n::IsRTL() ? OVERSCROLL_WEST : OVERSCROLL_EAST) &&
          controller.CanGoBack();
 }
 
 RenderWidgetHostViewAura* ToRenderWidgetHostViewAura(
     RenderWidgetHostView* view) {
   if (!view || RenderViewHostFactory::has_factory())
     return NULL;  // Can't cast to RenderWidgetHostViewAura in unit tests.
   RenderProcessHostImpl* process = static_cast<RenderProcessHostImpl*>(
       view->GetRenderWidgetHost()->GetProcess());
-  if (process->IsGuest())
-    return NULL;
+  DCHECK(!process->IsGuest());

[jam, 2013/11/14 17:42:15]

is this dcheck conclusive? i.e. can we still end up with a RHVGuest passed into
here that doesn't have RenderProcessHost::IsGuest?

[lazyboy, 2013/11/14 19:04:50]

IsGuest() = true here would mean either a. we incorrectly added WindowObserver
to a guest or b. for a WebContents, we navigated from a non-guest RVH to a guest
RVH.
Both of them is not expected in theory, so this DCHECK is covering these two
cases.

[lazyboy, 2013/11/14 21:34:55]

TouchEditable also uses this method, which means the DCHECK cannot be here,
reverted this change here.

   return static_cast<RenderWidgetHostViewAura*>(view);
 }
 
 // The window delegate for the overscroll window. This redirects trackpad events
 // to the web-contents window. The delegate destroys itself when the window is
 // destroyed.
 class OverscrollWindowDelegate : public ImageWindowDelegate {
  public:
   OverscrollWindowDelegate(WebContentsImpl* web_contents,
                            OverscrollMode overscroll_mode)
@@ skipping 1009 matching lines @@
 }
 
 DropData* WebContentsViewAura::GetDropData() const {
   return current_drop_data_.get();
 }
 
 gfx::Rect WebContentsViewAura::GetViewBounds() const {
   return window_->GetBoundsInScreen();
 }
 
+

[jam, 2013/11/14 17:42:15]

nit: undo

[lazyboy, 2013/11/14 19:04:50]

Done.

 ////////////////////////////////////////////////////////////////////////////////
 // WebContentsViewAura, WebContentsViewPort implementation:
 
 void WebContentsViewAura::CreateView(
     const gfx::Size& initial_size, gfx::NativeView context) {
   // NOTE: we ignore |initial_size| since in some cases it's wrong (such as
   // if the bookmark bar is not shown and you create a new tab). The right
   // value is set shortly after this, so its safe to ignore.
 
   aura::Env::CreateInstance();
@@ skipping 13 matching lines @@
     // explicitly add this WebContentsViewAura to their tree after they create
     // us.
     if (root_window) {
       aura::client::ParentWindowWithContext(
           window_.get(), root_window, root_window->GetBoundsInScreen());
     }
   }
   window_->layer()->SetMasksToBounds(true);
   window_->SetName("WebContentsViewAura");
 
-  window_observer_.reset(new WindowObserver(this));
+  // WindowObserver is not interesting and is problematic for Browser Plugin
+  // guests.
+  // The use cases for WindowObserver do not apply to Browser Plugins:
+  // 1) guests do not support NPAPI plugins.
+  // 2) guests' window bounds are supposed to come from its embedder.
+  if (!web_contents_->GetRenderProcessHost()->IsGuest())
+    window_observer_.reset(new WindowObserver(this));
 
   // delegate_->GetDragDestDelegate() creates a new delegate on every call.
   // Hence, we save a reference to it locally. Similar model is used on other
   // platforms as well.
   if (delegate_)
     drag_dest_delegate_ = delegate_->GetDragDestDelegate();
 }
 
 RenderWidgetHostView* WebContentsViewAura::CreateViewForWidget(
     RenderWidgetHost* render_widget_host) {
@@ skipping 465 matching lines @@
       event.location(),
       gfx::Screen::GetScreenFor(GetNativeView())->GetCursorScreenPoint(),
       ConvertAuraEventFlagsToWebInputEventModifiers(event.flags()));
   if (drag_dest_delegate_)
     drag_dest_delegate_->OnDrop();
   current_drop_data_.reset();
   return current_drag_op_;
 }
 
 }  // namespace content