[code coverage] Exclude Android from sandbox coverage.

Temporarily turn off the sandbox coverage file injection on Android
platform.

Also remove a stale TODO for Windows.

Bug: 985574
Change-Id: If5a9906cb5c9ef865e91c787d9046428ba78cb6d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1891468Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Sajjad Mirza <sajjadm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#711091}

content/child/child_thread_impl.cc

@@ -394,8 +394,8 @@ class ChildProcessImpl : public mojom::ChildProcess {
 
 #if BUILDFLAG(CLANG_COVERAGE)
   void SetCoverageFile(base::File file) override {
-    // TODO(crbug.com/988816) Fix this when we support coverage on Windows.
-#if defined(OS_POSIX)
+    // TODO(crbug.com/985574) Remove Android check when possible.
+#if defined(OS_POSIX) && !defined(OS_ANDROID)
     // Take the file descriptor so that |file| does not close it.
     int fd = file.TakePlatformFile();
     FILE* f = fdopen(fd, "r+b");