Remove pragmas for GRIT in modules/media_controls

To CL applies the compile options defined in
tools/grit/grit_rule.gni to media_controls_resource_loader.cc
by adding a deps to a grit rule, and removes
pragmas in the .cc file.

Bug: 839236
Change-Id: I7838d9775e091b10d5a9369c7fce176aced7cefb
Reviewed-on: https://chromium-review.googlesource.com/1043206Reviewed-by: Nico Weber <thakis@chromium.org>
Reviewed-by: Becca Hughes <beccahughes@chromium.org>
Commit-Queue: Hiroshige Hayashizaki <hiroshige@chromium.org>
Cr-Commit-Position: refs/heads/master@{#557328}

third_party/blink/renderer/modules/media_controls/BUILD.gn

@@ -83,6 +83,7 @@ blink_modules_sources("media_controls") {
   ]
 
   deps = [
+    ":media_controls_resources",
     "//services/service_manager/public/cpp",
     "//third_party/blink/public:media_controls_resources_header",
   ]

third_party/blink/renderer/modules/media_controls/media_controls_resource_loader.cc

@@ -30,16 +30,6 @@ MediaControlsResourceLoader::MediaControlsResourceLoader()
 
 MediaControlsResourceLoader::~MediaControlsResourceLoader() = default;
 
-// Official Android builds that have enable_resource_whitelist_generation
-// turned on will fail to compile due to an unknown-pragmas warning. In
-// Chromium this is expected, but in Blink the compiler treats warnings as
-// errors and so will fail to compile.
-#if defined(OS_WIN)
-#pragma warning(disable : 4068)
-#else
-#pragma GCC diagnostic push
-#pragma GCC diagnostic warning "-Wunknown-pragmas"
-#endif
 String MediaControlsResourceLoader::GetMediaControlsCSS() const {
   return ResourceBundleHelper::UncompressResourceAsString(
       RuntimeEnabledFeatures::ModernMediaControlsEnabled()
@@ -102,13 +92,6 @@ String MediaControlsResourceLoader::GetMediaInterstitialsStyleSheet() {
       IDR_UASTYLE_MEDIA_INTERSTITIALS_CSS);
 };
 
-// Re-enable the warnings.
-#if defined(OS_WIN)
-#pragma warning(default : 4068)
-#else
-#pragma GCC diagnostic pop
-#endif
-
 String MediaControlsResourceLoader::GetUAStyleSheet() {
   if (ShouldLoadAndroidCSS()) {
     return GetMediaControlsCSS() + GetMediaControlsAndroidCSS() +