Update to Chromium revision 6e53600d (#386251)

- Remove |accept_lang| parameter from CefJSDialogHandler::OnJSDialog
  and CefFormatUrlForSecurityDisplay (see https://crbug.com/336973#c36).
- Remove remaining NPAPI-related code including functions from
  cef_web_plugin.h (see https://crbug.com/493212#c55).
- Mac: 10.7+ deployment target is now required for client applications.
- Mac: Remove CefBrowserHost::SetWindowVisibility (issue #1375). No
  replacement is required for windowed rendering. Use WasHidden for
  off-screen rendering.
- Windows: Visual Studio 2015 Update 2 is now required when building
  CEF/Chromium.

patch/patches/pdfium_print_549365.patch

@@ -1,16 +1,16 @@
 diff --git fpdfsdk/fpdfview.cpp fpdfsdk/fpdfview.cpp
-index 4630ac1..9b5b36f 100644
+index e5a53da..7e3311a 100644
 --- fpdfsdk/fpdfview.cpp
 +++ fpdfsdk/fpdfview.cpp
-@@ -16,6 +16,7 @@
+@@ -18,6 +18,7 @@
+ #include "fpdfsdk/include/fsdk_define.h"
  #include "fpdfsdk/include/fsdk_mgr.h"
  #include "fpdfsdk/include/fsdk_rendercontext.h"
- #include "fpdfsdk/include/javascript/IJavaScript.h"
 +#include "fpdfsdk/include/jsapi/fxjs_v8.h"
+ #include "fpdfsdk/javascript/ijs_runtime.h"
  #include "public/fpdf_ext.h"
  #include "public/fpdf_progressive.h"
- #include "third_party/base/numerics/safe_conversions_impl.h"
-@@ -263,6 +264,7 @@ DLLEXPORT void STDCALL FPDF_DestroyLibrary() {
+@@ -266,6 +267,7 @@ DLLEXPORT void STDCALL FPDF_DestroyLibrary() {
  #endif  // PDF_ENABLE_XFA
    CPDF_ModuleMgr::Destroy();
    CFX_GEModule::Destroy();