DCHECK earlier if pepper flash is missing even though FLAPPER_AVAILABLE is defined.

chrome/common/chrome_content_client.cc

 // Copyright (c) 2012 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.
 
 #include "chrome/common/chrome_content_client.h"
 
 #include "base/command_line.h"
 #include "base/file_util.h"
 #include "base/path_service.h"
 #include "base/process_util.h"
@@ skipping 214 matching lines @@
         switches::kEnableBundledPpapiFlash);
 #endif
     bundled_flapper_enabled &= !CommandLine::ForCurrentProcess()->HasSwitch(
                                    switches::kDisableBundledPpapiFlash);
     if (!bundled_flapper_enabled)
       return;
 
 #if defined(FLAPPER_AVAILABLE)
     if (!PathService::Get(chrome::FILE_PEPPER_FLASH_PLUGIN, &plugin.path))
       return;
+    // It is an error to have FLAPPER_AVAILABLE defined but then not having the
+    // plugin file in place, but this happens in Chrome OS builds.
+    // Use --disable-bundled-ppapi-flash to skip this.
+    DCHECK(file_util::PathExists(plugin.path));
     flash_version = FLAPPER_VERSION_STRING;
 #else
     LOG(ERROR) << "PPAPI Flash not included at build time.";
     return;
 #endif  // FLAPPER_AVAILABLE
   }
 
   std::vector<std::string> flash_version_numbers;
   base::SplitString(flash_version, '.', &flash_version_numbers);
   if (flash_version_numbers.size() < 1)
@@ skipping 220 matching lines @@
   DCHECK(sandbox_profile_resource_id);
   if (sandbox_type == CHROME_SANDBOX_TYPE_NACL_LOADER) {
     *sandbox_profile_resource_id = IDR_NACL_SANDBOX_PROFILE;
     return true;
   }
   return false;
 }
 #endif
 
 }  // namespace chrome