Restore the chrome watcher pending relocation

chrome/app/main_dll_loader_win.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/app/main_dll_loader_win.h"
 
 #include <windows.h>  // NOLINT
 #include <shlwapi.h>  // NOLINT
 #include <stddef.h>
 #include <userenv.h>  // NOLINT
@@ skipping 185 matching lines @@
   int OnBeforeExit(int return_code, const base::FilePath& dll_path) override;
 
  private:
   std::unique_ptr<ChromeWatcherClient> chrome_watcher_client_;
 };
 
 void ChromeDllLoader::OnBeforeLaunch(const std::string& process_type,
                                      const base::FilePath& dll_path) {
   if (process_type.empty()) {
     RecordDidRun(dll_path);
+
+    // Get the function that determines whether uploads are enabled.
+    typedef bool (*GetUploadsEnabledFunction)(void);
+    static GetUploadsEnabledFunction get_uploads_enabled = nullptr;

[Sigurður Ásgeirsson, 2016/09/01 15:30:36]

You may want to check this with chrome-metrics folks, but I think gating
functionality on consent is strongly discouraged.

[Alexei Svitkine (slow), 2016/09/01 15:40:26]

Agreed. If you're just doing this to "save extra work since metrics won't be
reported to anywhere", please don't. We don't want consented users to have lower
performance than non consented users, since this discourages users from giving
consent.

Happy to discuss in more detail if the case is different from the above.

[manzagop (departed), 2016/09/01 16:02:49]

Done.

+    if (!get_uploads_enabled) {
+      get_uploads_enabled =
+          reinterpret_cast<GetUploadsEnabledFunction>(GetProcAddress(
+              GetModuleHandle(chrome::kChromeElfDllName), "GetUploadsEnabled"));
+      CHECK(get_uploads_enabled);
+    }
+
+    // Launch the watcher process if stats collection consent has been granted.
+    if (get_uploads_enabled()) {
+      base::FilePath exe_path;
+      if (PathService::Get(base::FILE_EXE, &exe_path)) {
+        chrome_watcher_client_.reset(new ChromeWatcherClient(
+            base::Bind(&GenerateChromeWatcherCommandLine, exe_path)));
+        chrome_watcher_client_->LaunchWatcher();
+      }
+    }
   } else {
     // Set non-browser processes up to be killed by the system after the browser
     // goes away. The browser uses the default shutdown order, which is 0x280.
     // Note that lower numbers here denote "kill later" and higher numbers mean
     // "kill sooner".
     // This gets rid of most of those unsighly sad tabs on logout and shutdown.
     ::SetProcessShutdownParameters(0x280 - 1, SHUTDOWN_NORETRY);
   }
 }
 
@@ skipping 22 matching lines @@
   }
 };
 
 MainDllLoader* MakeMainDllLoader() {
 #if defined(GOOGLE_CHROME_BUILD)
   return new ChromeDllLoader();
 #else
   return new ChromiumDllLoader();
 #endif
 }