Allow virtual keyboard window to access audio stream and speech api for voice input

ui/keyboard/keyboard_controller_proxy.cc

 // Copyright (c) 2013 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 "ui/keyboard/keyboard_controller_proxy.h"
 
 #include "content/public/browser/site_instance.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/browser/web_contents_delegate.h"
 #include "content/public/browser/web_contents_observer.h"
@@ skipping 19 matching lines @@
         params.url, params.referrer, params.transition, params.extra_headers);
     Observe(source);
     return source;
   }
 
   // Overridden from content::WebContentsObserver:
   virtual void WebContentsDestroyed(content::WebContents* contents) OVERRIDE {
     delete this;
   }
 
+  virtual void RequestMediaAccessPermission(
+    content::WebContents* web_contents,
+    const content::MediaStreamRequest& request,
+    const content::MediaResponseCallback& callback) OVERRIDE {

[sadrul, 2013/05/14 05:13:03]

I took a brief look at the code in ProcessMediaAccessRequest, and
WebContentsImpl::RequestMediaAccessPermission. It doesn't look like there is a
good way of doing all of the work from here without duplicating a lot of code
from browser/media/.

We don't want to move the entire KeyboardContentsDelegate into chrome. An
alternate solution for this would be to introduce
KeyboardControllerProxy::RequestAudioInput (or something like that). The chrome
implementation (in AshKeyboardControllerProxy) would interact with
MediaCaptureDevicesDispatcher. Note that the implementation should just accept
the request, without showing an infobar to the user. The default implementation
can deny the request.

KeyboardContentsDelegate should have a reference to the KCP, and call into its
RequestAudioInput from here.

+    const extensions::Extension* extension = NULL;
+    GURL origin(request.security_origin);
+    if (origin.SchemeIs(extensions::kExtensionScheme)) {
+      ExtensionService* extensions_service =
+          extensions::ExtensionSystem::Get(profile_)->extension_service();
+      extension = extensions_service->extensions()->GetByID(origin.host());
+      DCHECK(extension);
+    }
+
+    MediaCaptureDevicesDispatcher::GetInstance()->ProcessMediaAccessRequest(
+        web_contents, request, callback, extension);
+  }
+
   DISALLOW_COPY_AND_ASSIGN(KeyboardContentsDelegate);
 };
 
 }  // namespace
 
 namespace keyboard {
 
 KeyboardControllerProxy::KeyboardControllerProxy() {
 }
 
@@ skipping 18 matching lines @@
     keyboard_contents_->OpenURL(params);
   }
 
   return keyboard_contents_->GetView()->GetNativeView();
 }
 
 void KeyboardControllerProxy::SetupWebContents(content::WebContents* contents) {
 }
 
 }  // namespace keyboard