Browser Plugin: Simplify attachment logic

This CL is both code simplification and fixes a subtle bug.

Prior to this CL, we were dropping resizes between calls to BrowserPlugin::Attach
and BrowserPlugin::OnAttachACK. It seems AttachACK is now unnecessary (its functionality
was moved out of BrowserPlugin), and so we can simply get rid of it and the associated
attach_pending_ flag.

BUG=434827
TBR=kenrb@chromium.org for browser_plugin_messages.h IPC removal.

Review URL: https://codereview.chromium.org/736953005

Cr-Commit-Position: refs/heads/master@{#304919}

4 files changed, 10 insertions, 32 deletions

diff --git a/content/browser/browser_plugin/browser_plugin_guest.cc b/content/browser/browser_plugin/browser_plugin_guest.cc
index c2db313..544b869 100644
--- a/content/browser/browser_plugin/browser_plugin_guest.cc
+++ b/content/browser/browser_plugin/browser_plugin_guest.cc
@@ -251,10 +251,6 @@ void BrowserPluginGuest::Initialize(
         GetWebContents()->GetRenderViewHost());
     guest_rvh->SetInputMethodActive(true);
   }
-
-  // Inform the embedder of the guest's attachment.
-  SendMessageToEmbedder(
-      new BrowserPluginMsg_Attach_ACK(browser_plugin_instance_id_));
 }
 
 BrowserPluginGuest::~BrowserPluginGuest() {
diff --git a/content/common/browser_plugin/browser_plugin_messages.h b/content/common/browser_plugin/browser_plugin_messages.h
index 61fbdef..57070855 100644
--- a/content/common/browser_plugin/browser_plugin_messages.h
+++ b/content/common/browser_plugin/browser_plugin_messages.h
@@ -162,11 +162,6 @@ IPC_MESSAGE_ROUTED2(BrowserPluginHostMsg_ResizeGuest,
 // -----------------------------------------------------------------------------
 // These messages are from the browser process to the embedder.
 
-// This message is sent in response to a completed attachment of a guest
-// to a BrowserPlugin.
-IPC_MESSAGE_CONTROL1(BrowserPluginMsg_Attach_ACK,
-                     int /* browser_plugin_instance_id */)
-
 // When the guest crashes, the browser process informs the embedder through this
 // message.
 IPC_MESSAGE_CONTROL1(BrowserPluginMsg_GuestGone,
diff --git a/content/renderer/browser_plugin/browser_plugin.cc b/content/renderer/browser_plugin/browser_plugin.cc
index 39e49d2..f153a89 100644
--- a/content/renderer/browser_plugin/browser_plugin.cc
+++ b/content/renderer/browser_plugin/browser_plugin.cc
@@ -62,7 +62,6 @@ BrowserPlugin::BrowserPlugin(RenderViewImpl* render_view,
                              blink::WebFrame* frame,
                              scoped_ptr<BrowserPluginDelegate> delegate)
     : attached_(false),
-      attach_pending_(false),
       render_view_(render_view->AsWeakPtr()),
       render_view_routing_id_(render_view->GetRoutingID()),
       container_(NULL),
@@ -94,7 +93,6 @@ BrowserPlugin::~BrowserPlugin() {
 bool BrowserPlugin::OnMessageReceived(const IPC::Message& message) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(BrowserPlugin, message)
-    IPC_MESSAGE_HANDLER(BrowserPluginMsg_Attach_ACK, OnAttachACK)
     IPC_MESSAGE_HANDLER(BrowserPluginMsg_AdvanceFocus, OnAdvanceFocus)
     IPC_MESSAGE_HANDLER_GENERIC(BrowserPluginMsg_CompositorFrameSwapped,
                                 OnCompositorFrameSwapped(message))
@@ -122,8 +120,7 @@ void BrowserPlugin::UpdateDOMAttribute(const std::string& attribute_name,
 }
 
 void BrowserPlugin::Attach() {
-  if (ready()) {
-    attached_ = false;
+  if (attached()) {
     guest_crashed_ = false;
     EnableCompositing(false);
     if (compositing_helper_.get()) {
@@ -153,7 +150,7 @@ void BrowserPlugin::Attach() {
       browser_plugin_instance_id_,
       attach_params));
 
-  attach_pending_ = true;
+  attached_ = true;
 }
 
 void BrowserPlugin::DidCommitCompositorFrame() {
@@ -167,12 +164,6 @@ void BrowserPlugin::OnAdvanceFocus(int browser_plugin_instance_id,
   render_view_->GetWebView()->advanceFocus(reverse);
 }
 
-void BrowserPlugin::OnAttachACK(int browser_plugin_instance_id) {
-  DCHECK(!attached());
-  attached_ = true;
-  attach_pending_ = false;
-}
-
 void BrowserPlugin::OnCompositorFrameSwapped(const IPC::Message& message) {
   BrowserPluginMsg_CompositorFrameSwapped::Param param;
   if (!BrowserPluginMsg_CompositorFrameSwapped::Read(&message, &param))
@@ -279,7 +270,7 @@ void BrowserPlugin::UpdateDeviceScaleFactor() {
 }
 
 void BrowserPlugin::UpdateGuestFocusState() {
-  if (!ready())
+  if (!attached())
     return;
   bool should_be_focused = ShouldGuestBeFocused();
   browser_plugin_manager()->Send(new BrowserPluginHostMsg_SetFocus(
@@ -405,7 +396,6 @@ void BrowserPlugin::paint(WebCanvas* canvas, const WebRect& rect) {
 bool BrowserPlugin::ShouldForwardToBrowserPlugin(
     const IPC::Message& message) {
   switch (message.type()) {
-    case BrowserPluginMsg_Attach_ACK::ID:
     case BrowserPluginMsg_AdvanceFocus::ID:
     case BrowserPluginMsg_CompositorFrameSwapped::ID:
     case BrowserPluginMsg_GuestGone::ID:
@@ -473,7 +463,7 @@ void BrowserPlugin::updateVisibility(bool visible) {
     return;
 
   visible_ = visible;
-  if (!ready())
+  if (!attached())
     return;
 
   if (compositing_helper_.get())
@@ -491,7 +481,7 @@ bool BrowserPlugin::acceptsInputEvents() {
 
 bool BrowserPlugin::handleInputEvent(const blink::WebInputEvent& event,
                                      blink::WebCursorInfo& cursor_info) {
-  if (guest_crashed_ || !ready())
+  if (guest_crashed_ || !attached())
     return false;
 
   if (event.type == blink::WebInputEvent::ContextMenu)
@@ -521,7 +511,7 @@ bool BrowserPlugin::handleDragStatusUpdate(blink::WebDragStatus drag_status,
                                            blink::WebDragOperationsMask mask,
                                            const blink::WebPoint& position,
                                            const blink::WebPoint& screen) {
-  if (guest_crashed_ || !ready())
+  if (guest_crashed_ || !attached())
     return false;
   browser_plugin_manager()->Send(
       new BrowserPluginHostMsg_DragStatusUpdate(
@@ -583,7 +573,7 @@ bool BrowserPlugin::setComposition(
     const blink::WebVector<blink::WebCompositionUnderline>& underlines,
     int selectionStart,
     int selectionEnd) {
-  if (!ready())
+  if (!attached())
     return false;
   std::vector<blink::WebCompositionUnderline> std_underlines;
   for (size_t i = 0; i < underlines.size(); ++i) {
@@ -603,7 +593,7 @@ bool BrowserPlugin::setComposition(
 bool BrowserPlugin::confirmComposition(
     const blink::WebString& text,
     blink::WebWidget::ConfirmCompositionBehavior selectionBehavior) {
-  if (!ready())
+  if (!attached())
     return false;
   bool keep_selection = (selectionBehavior == blink::WebWidget::KeepSelection);
   browser_plugin_manager()->Send(new BrowserPluginHostMsg_ImeConfirmComposition(
@@ -616,7 +606,7 @@ bool BrowserPlugin::confirmComposition(
 }
 
 void BrowserPlugin::extendSelectionAndDelete(int before, int after) {
-  if (!ready())
+  if (!attached())
     return;
   browser_plugin_manager()->Send(
       new BrowserPluginHostMsg_ExtendSelectionAndDelete(
diff --git a/content/renderer/browser_plugin/browser_plugin.h b/content/renderer/browser_plugin/browser_plugin.h
index d072e7b..f0d9601 100644
--- a/content/renderer/browser_plugin/browser_plugin.h
+++ b/content/renderer/browser_plugin/browser_plugin.h
@@ -37,7 +37,6 @@ class CONTENT_EXPORT BrowserPlugin :
   int render_view_routing_id() const { return render_view_routing_id_; }
   int browser_plugin_instance_id() const { return browser_plugin_instance_id_; }
   bool attached() const { return attached_; }
-  bool ready() const { return attached_ || attach_pending_; }
   BrowserPluginManager* browser_plugin_manager() const {
     return browser_plugin_manager_.get();
   }
@@ -170,7 +169,6 @@ class CONTENT_EXPORT BrowserPlugin :
   // IPC message handlers.
   // Please keep in alphabetical order.
   void OnAdvanceFocus(int instance_id, bool reverse);
-  void OnAttachACK(int browser_plugin_instance_id);
   void OnCompositorFrameSwapped(const IPC::Message& message);
   void OnGuestGone(int instance_id);
   void OnSetContentsOpaque(int instance_id, bool opaque);
@@ -181,9 +179,8 @@ class CONTENT_EXPORT BrowserPlugin :
   void OnShouldAcceptTouchEvents(int instance_id, bool accept);
 
   // This indicates whether this BrowserPlugin has been attached to a
-  // WebContents.
+  // WebContents and is ready to receive IPCs.
   bool attached_;
-  bool attach_pending_;
   const base::WeakPtr<RenderViewImpl> render_view_;
   // We cache the |render_view_|'s routing ID because we need it on destruction.
   // If the |render_view_| is destroyed before the BrowserPlugin is destroyed