Add plugin placeholder and policy support (issue #1708)

- Default plugin loading policy can be specified using the new
  `--plugin-policy=[allow|block|detect]` command-line flag.
- Move CefRequestHandler::OnBeforePluginLoad to
  CefRequestContextHandler and add a new policy argument that
  supports different actions (allow, block, detect, disable) on a
  per-plugin-instance basis.
- Add CefContextMenuHandler::RunContextMenu for providing a custom
  context menu implementation.
- Add CefResourceBundleHandler::GetDataResourceForScale for
  returning scaled resources (issue #1272).
- Add CefResourceBundle for retrieving resources from the resource
  bundle (*.pak) files loaded by CEF during startup or via the
  CefResourceBundleHandler.
- Linux: Fix Debug build IO access warning with CefGetMimeType.
- cef_unittests: Move the refcounting implementation from TestHandler
  to subclasses in order to support interface inheritance from
  subclasses.

include/cef_resource_bundle.h

@@ -0,0 +1,99 @@
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//    * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//    * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//    * Neither the name of Google Inc. nor the name Chromium Embedded
+// Framework nor the names of its contributors may be used to endorse
+// or promote products derived from this software without specific prior
+// written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// ---------------------------------------------------------------------------
+//
+// The contents of this file must follow a specific format in order to
+// support the CEF translator tool. See the translator.README.txt file in the
+// tools directory for more information.
+//
+
+#ifndef CEF_INCLUDE_CEF_RESOURCE_BUNDLE_H_
+#define CEF_INCLUDE_CEF_RESOURCE_BUNDLE_H_
+#pragma once
+
+#include "include/cef_base.h"
+
+///
+// Class used for retrieving resources from the resource bundle (*.pak) files
+// loaded by CEF during startup or via the CefResourceBundleHandler returned
+// from CefApp::GetResourceBundleHandler. See CefSettings for additional options
+// related to resource bundle loading. The methods of this class may be called
+// on any thread unless otherwise indicated.
+///
+/*--cef(source=library,no_debugct_check)--*/
+class CefResourceBundle : public virtual CefBase {
+ public:
+  typedef cef_scale_factor_t ScaleFactor;
+
+  ///
+  // Returns the global resource bundle instance.
+  ///
+  /*--cef()--*/
+  static CefRefPtr<CefResourceBundle> GetGlobal();
+
+  ///
+  // Returns the localized string for the specified |string_id| or an empty
+  // string if the value is not found. Include cef_pack_strings.h for a listing
+  // of valid string ID values.
+  ///
+  /*--cef()--*/
+  virtual CefString GetLocalizedString(int string_id) =0;
+
+  ///
+  // Retrieves the contents of the specified scale independent |resource_id|.
+  // If the value is found then |data| and |data_size| will be populated and
+  // this method will return true. If the value is not found then this method
+  // will return false. The returned |data| pointer will remain resident in
+  // memory and should not be freed. Include cef_pack_resources.h for a listing
+  // of valid resource ID values.
+  ///
+  /*--cef()--*/
+  virtual bool GetDataResource(int resource_id,
+                               void*& data,
+                               size_t& data_size) =0;
+
+  ///
+  // Retrieves the contents of the specified |resource_id| nearest the scale
+  // factor |scale_factor|. Use a |scale_factor| value of SCALE_FACTOR_NONE for
+  // scale independent resources or call GetDataResource instead. If the value
+  // is found then |data| and |data_size| will be populated and this method will
+  // return true. If the value is not found then this method will return false.
+  // The returned |data| pointer will remain resident in memory and should not
+  // be freed. Include cef_pack_resources.h for a listing of valid resource ID
+  // values.
+  ///
+  /*--cef()--*/
+  virtual bool GetDataResourceForScale(int resource_id,
+                                       ScaleFactor scale_factor,
+                                       void*& data,
+                                       size_t& data_size) =0;
+};
+
+#endif  // CEF_INCLUDE_CEF_RESOURCE_BUNDLE_H_