Introduce ExtensionHostDelegate, use it for media access requests

As part of the app_shell/extensions refactoring project we're trying to move
ExtensionHost to src/extensions.

* Break ExtensionHost's dependency on chrome/browser/media by delegating out
  media access requests. Some extension background pages do make these requests
  e.g. the Chromecast extension.
* Also use it for tab creation requests.
* Now that there are 5 methods delegated out of ExtensionHost introduce
  ExtensionHostDelegate to implement them and reduce the size of the
  ExtensionsBrowserClient interface.

BUG=321341
TEST=browser_tests *Extension* and *Media*

Review URL: https://codereview.chromium.org/203953003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@257915 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 73 insertions, 27 deletions

diff --git a/extensions/browser/extension_host_delegate.h b/extensions/browser/extension_host_delegate.h
new file mode 100644
index 0000000..0bf52a4
--- /dev/null
+++ b/extensions/browser/extension_host_delegate.h
@@ -0,0 +1,63 @@
+// Copyright 2014 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.
+
+#ifndef EXTENSIONS_BROWSER_EXTENSION_HOST_DELEGATE_H_
+#define EXTENSIONS_BROWSER_EXTENSION_HOST_DELEGATE_H_
+
+#include <string>
+
+#include "content/public/common/media_stream_request.h"
+#include "ui/base/window_open_disposition.h"
+
+namespace content {
+class JavaScriptDialogManager;
+class WebContents;
+}
+
+namespace gfx {
+class Rect;
+}
+
+namespace extensions {
+class Extension;
+class ExtensionHost;
+
+// A delegate to support functionality that cannot exist in the extensions
+// module. This is not an inner class of ExtensionHost to allow it to be forward
+// declared.
+class ExtensionHostDelegate {
+ public:
+  virtual ~ExtensionHostDelegate() {}
+
+  // Called after the hosting |web_contents| for an extension is created. The
+  // implementation may wish to add preference observers to |web_contents|.
+  virtual void OnExtensionHostCreated(content::WebContents* web_contents) = 0;
+
+  // Called after |host| creates a RenderView for an extension.
+  virtual void OnRenderViewCreatedForBackgroundPage(ExtensionHost* host) = 0;
+
+  // Returns the embedder's JavaScriptDialogManager or NULL if the embedder
+  // does not support JavaScript dialogs.
+  virtual content::JavaScriptDialogManager* GetJavaScriptDialogManager() = 0;
+
+  // Creates a new tab or popup window with |web_contents|. The embedder may
+  // choose to do nothing if tabs and popups are not supported.
+  virtual void CreateTab(content::WebContents* web_contents,
+                         const std::string& extension_id,
+                         WindowOpenDisposition disposition,
+                         const gfx::Rect& initial_pos,
+                         bool user_gesture) = 0;
+
+  // Requests access to an audio or video media stream. Invokes |callback|
+  // with the response.
+  virtual void ProcessMediaAccessRequest(
+      content::WebContents* web_contents,
+      const content::MediaStreamRequest& request,
+      const content::MediaResponseCallback& callback,
+      const Extension* extension) = 0;
+};
+
+}  // namespace extensions
+
+#endif  // EXTENSIONS_BROWSER_EXTENSION_HOST_DELEGATE_H_
diff --git a/extensions/browser/extensions_browser_client.h b/extensions/browser/extensions_browser_client.h
index b994cca..2e3d26d 100644
--- a/extensions/browser/extensions_browser_client.h
+++ b/extensions/browser/extensions_browser_client.h
@@ -19,7 +19,6 @@ class CommandLine;
 
 namespace content {
 class BrowserContext;
-class JavaScriptDialogManager;
 class WebContents;
 }
 
@@ -28,7 +27,7 @@ namespace extensions {
 class ApiActivityMonitor;
 class AppSorting;
 class Extension;
-class ExtensionHost;
+class ExtensionHostDelegate;
 class ExtensionSystem;
 class ExtensionSystemProvider;
 
@@ -98,12 +97,8 @@ class ExtensionsBrowserClient {
   virtual bool IsBackgroundPageAllowed(
       content::BrowserContext* context) const = 0;
 
-  // Called after the hosting |web_contents| for an extension is created. The
-  // implementation may wish to add preference observers to |web_contents|.
-  virtual void OnExtensionHostCreated(content::WebContents* web_contents) = 0;
-
-  // Called after |host| creates a RenderView for an extension.
-  virtual void OnRenderViewCreatedForBackgroundPage(ExtensionHost* host) = 0;
+  // Creates a new ExtensionHostDelegate instance.
+  virtual scoped_ptr<ExtensionHostDelegate> CreateExtensionHostDelegate() = 0;
 
   // Returns true if the client version has updated since the last run. Called
   // once each time the extensions system is loaded per browser_context. The
@@ -121,10 +116,6 @@ class ExtensionsBrowserClient {
   // Return true if the system is run in forced app mode.
   virtual bool IsRunningInForcedAppMode() = 0;
 
-  // Returns the embedder's JavaScriptDialogManager or NULL if the embedder
-  // does not support JavaScript dialogs.
-  virtual content::JavaScriptDialogManager* GetJavaScriptDialogManager() = 0;
-
   // Returns the embedder's ApiActivityMonitor for |context|. Returns NULL if
   // the embedder does not monitor extension API activity.
   virtual ApiActivityMonitor* GetApiActivityMonitor(
diff --git a/extensions/browser/test_extensions_browser_client.cc b/extensions/browser/test_extensions_browser_client.cc
index b9cd561..739450b 100644
--- a/extensions/browser/test_extensions_browser_client.cc
+++ b/extensions/browser/test_extensions_browser_client.cc
@@ -6,6 +6,7 @@
 
 #include "content/public/browser/browser_context.h"
 #include "extensions/browser/app_sorting.h"
+#include "extensions/browser/extension_host_delegate.h"
 
 using content::BrowserContext;
 
@@ -97,11 +98,10 @@ bool TestExtensionsBrowserClient::IsBackgroundPageAllowed(
   return true;
 }
 
-void TestExtensionsBrowserClient::OnExtensionHostCreated(
-    content::WebContents* web_contents) {}
-
-void TestExtensionsBrowserClient::OnRenderViewCreatedForBackgroundPage(
-    ExtensionHost* host) {}
+scoped_ptr<ExtensionHostDelegate>
+TestExtensionsBrowserClient::CreateExtensionHostDelegate() {
+  return scoped_ptr<ExtensionHostDelegate>();
+}
 
 bool TestExtensionsBrowserClient::DidVersionUpdate(BrowserContext* context) {
   return false;
@@ -115,11 +115,6 @@ scoped_ptr<AppSorting> TestExtensionsBrowserClient::CreateAppSorting() {
 
 bool TestExtensionsBrowserClient::IsRunningInForcedAppMode() { return false; }
 
-content::JavaScriptDialogManager*
-TestExtensionsBrowserClient::GetJavaScriptDialogManager() {
-  return NULL;
-}
-
 ApiActivityMonitor* TestExtensionsBrowserClient::GetApiActivityMonitor(
     BrowserContext* context) {
   return NULL;
diff --git a/extensions/browser/test_extensions_browser_client.h b/extensions/browser/test_extensions_browser_client.h
index 538fc0c..19f33d7 100644
--- a/extensions/browser/test_extensions_browser_client.h
+++ b/extensions/browser/test_extensions_browser_client.h
@@ -48,16 +48,12 @@ class TestExtensionsBrowserClient : public ExtensionsBrowserClient {
       content::BrowserContext* context) const OVERRIDE;
   virtual bool IsBackgroundPageAllowed(content::BrowserContext* context) const
       OVERRIDE;
-  virtual void OnExtensionHostCreated(content::WebContents* web_contents)
-      OVERRIDE;
-  virtual void OnRenderViewCreatedForBackgroundPage(ExtensionHost* host)
+  virtual scoped_ptr<ExtensionHostDelegate> CreateExtensionHostDelegate()
       OVERRIDE;
   virtual bool DidVersionUpdate(content::BrowserContext* context) OVERRIDE;
   virtual void PermitExternalProtocolHandler() OVERRIDE;
   virtual scoped_ptr<AppSorting> CreateAppSorting() OVERRIDE;
   virtual bool IsRunningInForcedAppMode() OVERRIDE;
-  virtual content::JavaScriptDialogManager* GetJavaScriptDialogManager()
-      OVERRIDE;
   virtual ApiActivityMonitor* GetApiActivityMonitor(
       content::BrowserContext* context) OVERRIDE;
   virtual ExtensionSystemProvider* GetExtensionSystemFactory() OVERRIDE;
diff --git a/extensions/extensions.gyp b/extensions/extensions.gyp
index b13f128..8debbf4 100644
--- a/extensions/extensions.gyp
+++ b/extensions/extensions.gyp
@@ -230,6 +230,7 @@
         'browser/event_listener_map.h',
         'browser/event_router.cc',
         'browser/event_router.h',
+        'browser/extension_host_delegate.h',
         'browser/extension_error.cc',
         'browser/extension_error.h',
         'browser/extension_function.cc',