Implement "Save image as" for canvas (blink side).

Source/web/AssertMatchingEnums.cpp

 /*
  * Copyright (C) 2012 Google Inc. 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
@@ skipping 569 matching lines @@
 
 COMPILE_ASSERT_MATCHING_ENUM(WebURLRequest::PriorityUnresolved, ResourceLoadPriorityUnresolved);
 COMPILE_ASSERT_MATCHING_ENUM(WebURLRequest::PriorityVeryLow, ResourceLoadPriorityVeryLow);
 COMPILE_ASSERT_MATCHING_ENUM(WebURLRequest::PriorityLow, ResourceLoadPriorityLow);
 COMPILE_ASSERT_MATCHING_ENUM(WebURLRequest::PriorityMedium, ResourceLoadPriorityMedium);
 COMPILE_ASSERT_MATCHING_ENUM(WebURLRequest::PriorityHigh, ResourceLoadPriorityHigh);
 COMPILE_ASSERT_MATCHING_ENUM(WebURLRequest::PriorityVeryHigh, ResourceLoadPriorityVeryHigh);
 
 COMPILE_ASSERT_MATCHING_ENUM(WebNavigationPolicyIgnore, NavigationPolicyIgnore);
 COMPILE_ASSERT_MATCHING_ENUM(WebNavigationPolicyDownload, NavigationPolicyDownload);
+COMPILE_ASSERT_MATCHING_ENUM(WebNavigationPolicyDownloadTo, NavigationPolicyDownloadTo);
 COMPILE_ASSERT_MATCHING_ENUM(WebNavigationPolicyCurrentTab, NavigationPolicyCurrentTab);
 COMPILE_ASSERT_MATCHING_ENUM(WebNavigationPolicyNewBackgroundTab, NavigationPolicyNewBackgroundTab);
 COMPILE_ASSERT_MATCHING_ENUM(WebNavigationPolicyNewForegroundTab, NavigationPolicyNewForegroundTab);
 COMPILE_ASSERT_MATCHING_ENUM(WebNavigationPolicyNewWindow, NavigationPolicyNewWindow);
 COMPILE_ASSERT_MATCHING_ENUM(WebNavigationPolicyNewPopup, NavigationPolicyNewPopup);
 
 COMPILE_ASSERT_MATCHING_ENUM(WebStandardCommit, StandardCommit);
 COMPILE_ASSERT_MATCHING_ENUM(WebBackForwardCommit, BackForwardCommit);
 COMPILE_ASSERT_MATCHING_ENUM(WebInitialCommitInChildFrame, InitialCommitInChildFrame);
 COMPILE_ASSERT_MATCHING_ENUM(WebHistoryInertCommit, HistoryInertCommit);
@@ skipping 11 matching lines @@
 COMPILE_ASSERT_MATCHING_ENUM(WebCustomHandlersRegistered, NavigatorContentUtilsClient::CustomHandlersRegistered);
 COMPILE_ASSERT_MATCHING_ENUM(WebCustomHandlersDeclined, NavigatorContentUtilsClient::CustomHandlersDeclined);
 
 COMPILE_ASSERT_MATCHING_ENUM(WebTouchActionNone, TouchActionNone);
 COMPILE_ASSERT_MATCHING_ENUM(WebTouchActionAuto, TouchActionAuto);
 COMPILE_ASSERT_MATCHING_ENUM(WebTouchActionPanX, TouchActionPanX);
 COMPILE_ASSERT_MATCHING_ENUM(WebTouchActionPanY, TouchActionPanY);
 COMPILE_ASSERT_MATCHING_ENUM(WebTouchActionPinchZoom, TouchActionPinchZoom);
 
 COMPILE_ASSERT_MATCHING_UINT64(kSerializedScriptValueVersion, SerializedScriptValue::wireFormatVersion);