Allow webview API in an unblessed extension process

chrome/browser/extensions/api/webview/webview_api.h

 // 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.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_API_WEBVIEW_WEBVIEW_API_H_
 #define CHROME_BROWSER_EXTENSIONS_API_WEBVIEW_WEBVIEW_API_H_
 
 #include "chrome/browser/extensions/api/execute_code_function.h"
+#include "chrome/browser/guestview/webview/webview_guest.h"
+
+// WARNING: Webview could be loaded in an unblessed context, thus any new
+// APIs must extend WebviewExtensionFunction/WebviewExecuteCodeFunction which

[not at google - send to devlin, 2013/09/25 23:46:46]

FWIW, it's not totally clear to me (i.e. not clear just from this file) how
WebviewExecuteCodeFunction actually does this (how it's safe); overriding
GetScriptExecutor is a bit vague. A safer way to structure this would be to
delegate to ExecuteScriptFunction rather than extending it, and extend
WebviewExtensionFunction instead. But that would be a more significant change.

[guohui, 2013/09/26 13:58:00]

TODO added.

+// do a process ID check to prevent abuse by normal renderer processes.
 
 namespace extensions {
 
-class WebviewClearDataFunction : public AsyncExtensionFunction {
+// An abstract base class for async webview APIs. It does a process ID check
+// in RunImpl, and then calls RunImplSafe which must be overriden by all
+// subclasses.
+class WebviewExtensionFunction : public AsyncExtensionFunction {
+ public:
+   WebviewExtensionFunction() {}
+
+ protected:
+  virtual ~WebviewExtensionFunction() {}
+
+  // ExtensionFunction implementation.
+  virtual bool RunImpl() OVERRIDE FINAL;
+
+ private:
+  virtual bool RunImplSafe(WebViewGuest* guest) = 0;
+};
+
+class WebviewClearDataFunction : public WebviewExtensionFunction {
  public:
   DECLARE_EXTENSION_FUNCTION("webview.clearData", WEBVIEW_CLEARDATA);
 
   WebviewClearDataFunction();
 
  protected:
   virtual ~WebviewClearDataFunction();
 
-  // ExtensionFunction implementation.
-  virtual bool RunImpl() OVERRIDE;
+ private:
+  virtual bool RunImplSafe(WebViewGuest* guest);
 
- private:
   uint32 GetRemovalMask();
   void ClearDataDone();
 
   // Removal start time.
   base::Time remove_since_;
   // Removal mask, corresponds to StoragePartition::RemoveDataMask enum.
   uint32 remove_mask_;
   // Tracks any data related or parse errors.
   bool bad_message_;
 
   DISALLOW_COPY_AND_ASSIGN(WebviewClearDataFunction);
 };
 
 class WebviewExecuteCodeFunction : public extensions::ExecuteCodeFunction {
  public:
   WebviewExecuteCodeFunction();
 
  protected:
   virtual ~WebviewExecuteCodeFunction();
 
   // Initialize |details_| if it hasn't already been.
   virtual bool Init() OVERRIDE;
   virtual bool ShouldInsertCSS() const OVERRIDE;
   virtual bool CanExecuteScriptOnPage() OVERRIDE;
-  virtual extensions::ScriptExecutor* GetScriptExecutor() OVERRIDE;
+  // Guarded by a process ID check.
+  virtual extensions::ScriptExecutor* GetScriptExecutor() OVERRIDE FINAL;
   virtual bool IsWebView() const OVERRIDE;
 
  private:
   // Contains extension resource built from path of file which is
   // specified in JSON arguments.
   extensions::ExtensionResource resource_;
 
   int guest_instance_id_;
 
   DISALLOW_COPY_AND_ASSIGN(WebviewExecuteCodeFunction);
@@ skipping 25 matching lines @@
   virtual ~WebviewInsertCSSFunction() {}
 
   virtual bool ShouldInsertCSS() const OVERRIDE;
 
   DECLARE_EXTENSION_FUNCTION("webview.insertCSS", WEBVIEW_INSERTCSS)
 
  private:
   DISALLOW_COPY_AND_ASSIGN(WebviewInsertCSSFunction);
 };
 
-class WebviewGoFunction : public AsyncExtensionFunction {
+class WebviewGoFunction : public WebviewExtensionFunction {
  public:
   DECLARE_EXTENSION_FUNCTION("webview.go", WEBVIEW_GO);
 
   WebviewGoFunction();
 
  protected:
   virtual ~WebviewGoFunction();
 
-  // ExtensionFunction implementation.
-  virtual bool RunImpl() OVERRIDE;
+ private:
+  virtual bool RunImplSafe(WebViewGuest* guest);
 
- private:
   DISALLOW_COPY_AND_ASSIGN(WebviewGoFunction);
 };
 
-class WebviewReloadFunction : public AsyncExtensionFunction {
+class WebviewReloadFunction : public WebviewExtensionFunction {
  public:
   DECLARE_EXTENSION_FUNCTION("webview.reload", WEBVIEW_RELOAD);
 
   WebviewReloadFunction();
 
  protected:
   virtual ~WebviewReloadFunction();
 
-  // ExtensionFunction implementation.
-  virtual bool RunImpl() OVERRIDE;
+ private:
+  virtual bool RunImplSafe(WebViewGuest* guest);
 
- private:
   DISALLOW_COPY_AND_ASSIGN(WebviewReloadFunction);
 };
 
-class WebviewSetPermissionFunction : public AsyncExtensionFunction {
+class WebviewSetPermissionFunction : public WebviewExtensionFunction {
  public:
   DECLARE_EXTENSION_FUNCTION("webview.setPermission", WEBVIEW_SETPERMISSION);
 
   WebviewSetPermissionFunction();
 
  protected:
   virtual ~WebviewSetPermissionFunction();
 
-  // ExtensionFunction implementation.
-  virtual bool RunImpl() OVERRIDE;
+ private:
+  virtual bool RunImplSafe(WebViewGuest* guest);
 
- private:
   DISALLOW_COPY_AND_ASSIGN(WebviewSetPermissionFunction);
 };
 
-class WebviewStopFunction : public AsyncExtensionFunction {
+class WebviewStopFunction : public WebviewExtensionFunction {
  public:
   DECLARE_EXTENSION_FUNCTION("webview.stop", WEBVIEW_STOP);
 
   WebviewStopFunction();
 
  protected:
   virtual ~WebviewStopFunction();
 
-  // ExtensionFunction implementation.
-  virtual bool RunImpl() OVERRIDE;
+ private:
+  virtual bool RunImplSafe(WebViewGuest* guest);
 
- private:
   DISALLOW_COPY_AND_ASSIGN(WebviewStopFunction);
 };
 
-class WebviewTerminateFunction : public AsyncExtensionFunction {
+class WebviewTerminateFunction : public WebviewExtensionFunction {
  public:
   DECLARE_EXTENSION_FUNCTION("webview.terminate", WEBVIEW_TERMINATE);
 
   WebviewTerminateFunction();
 
  protected:
   virtual ~WebviewTerminateFunction();
 
-  // ExtensionFunction implementation.
-  virtual bool RunImpl() OVERRIDE;
+ private:
+  virtual bool RunImplSafe(WebViewGuest* guest);
 
- private:
   DISALLOW_COPY_AND_ASSIGN(WebviewTerminateFunction);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_WEBVIEW_WEBVIEW_API_H_