Make extension APIs work in MimeHandlerView.

This will make some zoom functionality work in pdf viewer as they rely on
tabs.setZoomSettings/tabs.setZoom.

BUG=416332
Test=Load chrome with --enable-mime-handler-view and --out-of-process-pdf
Navigate to a pdf file, see ctrl+/- or zooming through browser menu work.
Ctrl + wheel still doesn't work, will fix that in a follow up CL.

Review URL: https://codereview.chromium.org/597653002

Cr-Commit-Position: refs/heads/master@{#296295}

extensions/browser/guest_view/mime_handler_view/mime_handler_view_guest.cc

@@ -14,9 +14,11 @@
 #include "extensions/browser/guest_view/mime_handler_view/mime_handler_view_constants.h"
 #include "extensions/browser/guest_view/mime_handler_view/mime_handler_view_guest_delegate.h"
 #include "extensions/browser/process_manager.h"
+#include "extensions/common/extension_messages.h"
 #include "extensions/common/feature_switch.h"
 #include "extensions/common/guest_view/guest_view_constants.h"
 #include "extensions/strings/grit/extensions_strings.h"
+#include "ipc/ipc_message_macros.h"
 #include "net/base/url_util.h"
 
 using content::WebContents;
@@ -47,6 +49,14 @@ MimeHandlerViewGuest::MimeHandlerViewGuest(
 MimeHandlerViewGuest::~MimeHandlerViewGuest() {
 }
 
+WindowController* MimeHandlerViewGuest::GetExtensionWindowController() const {
+  return NULL;
+}
+
+WebContents* MimeHandlerViewGuest::GetAssociatedWebContents() const {
+  return web_contents();
+}
+
 const char* MimeHandlerViewGuest::GetAPINamespace() const {
   return "mimeHandlerViewGuestInternal";
 }
@@ -115,6 +125,8 @@ void MimeHandlerViewGuest::DidAttachToEmbedder() {
 }
 
 void MimeHandlerViewGuest::DidInitialize() {
+  extension_function_dispatcher_.reset(
+      new ExtensionFunctionDispatcher(browser_context(), this));
   if (delegate_)
     delegate_->AttachHelpers();
 }
@@ -135,4 +147,21 @@ void MimeHandlerViewGuest::HandleKeyboardEvent(
                                                               event);
 }
 
+bool MimeHandlerViewGuest::OnMessageReceived(const IPC::Message& message) {
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP(MimeHandlerViewGuest, message)
+    IPC_MESSAGE_HANDLER(ExtensionHostMsg_Request, OnRequest)
+    IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP()
+  return handled;
+}
+
+void MimeHandlerViewGuest::OnRequest(
+    const ExtensionHostMsg_Request_Params& params) {
+  if (extension_function_dispatcher_) {
+    extension_function_dispatcher_->Dispatch(
+        params, web_contents()->GetRenderViewHost());
+  }
+}
+
 }  // namespace extensions

extensions/browser/guest_view/mime_handler_view/mime_handler_view_guest.h

@@ -5,19 +5,25 @@
 #ifndef EXTENSIONS_BROWSER_GUEST_VIEW_MIME_HANDLER_VIEW_MIME_HANDLER_VIEW_GUEST_H_
 #define EXTENSIONS_BROWSER_GUEST_VIEW_MIME_HANDLER_VIEW_MIME_HANDLER_VIEW_GUEST_H_
 
+#include "extensions/browser/extension_function_dispatcher.h"
 #include "extensions/browser/guest_view/guest_view.h"
 
 namespace extensions {
 
 class MimeHandlerViewGuestDelegate;
 
-class MimeHandlerViewGuest : public GuestView<MimeHandlerViewGuest> {
+class MimeHandlerViewGuest : public GuestView<MimeHandlerViewGuest>,
+                             public ExtensionFunctionDispatcher::Delegate {
  public:
   static GuestViewBase* Create(content::BrowserContext* browser_context,
                                int guest_instance_id);
 
   static const char Type[];
 
+  // ExtensionFunctionDispatcher::Delegate implementation.
+  virtual WindowController* GetExtensionWindowController() const OVERRIDE;
+  virtual content::WebContents* GetAssociatedWebContents() const OVERRIDE;
+
   // GuestViewBase implementation.
   virtual const char* GetAPINamespace() const OVERRIDE;
   virtual int GetTaskPrefix() const OVERRIDE;
@@ -35,12 +41,18 @@ class MimeHandlerViewGuest : public GuestView<MimeHandlerViewGuest> {
       content::WebContents* source,
       const content::NativeWebKeyboardEvent& event) OVERRIDE;
 
+  // content::WebContentsObserver implementation.
+  virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
+
  private:
   MimeHandlerViewGuest(content::BrowserContext* browser_context,
                        int guest_instance_id);
   virtual ~MimeHandlerViewGuest();
 
+  void OnRequest(const ExtensionHostMsg_Request_Params& params);
+
   scoped_ptr<MimeHandlerViewGuestDelegate> delegate_;
+  scoped_ptr<ExtensionFunctionDispatcher> extension_function_dispatcher_;
 
   DISALLOW_COPY_AND_ASSIGN(MimeHandlerViewGuest);
 };