refactor: move text-to-speech out of chromium_src (#15024)

* chore: add tts patch and buildflag, makes tts work again

* chore: add tts patch and buildflag, makes tts work again

* fix: make things compile

* build: add relevant tts files for linux

* fix: update patch and patch description, should now compile on mac

* build: move chrome specific sources under chromium_src:chrome target

* build: enable_extensions again

We are depending on them, check `//electron/chromium_src:chrome` target
for more info.

* fix: update tts.patch to receive notifications about browser context destruction

* fix: extend browser process from chrome layer

The global state g_browser_process is shared between //chrome
and //electron.

* spec: add basic speech synthesis test

* spec: skip speech tests on ci

* build: fix compilation on windows

atom/renderer/renderer_client_base.cc

@@ -20,7 +20,6 @@
 #include "base/strings/string_split.h"
 #include "base/strings/stringprintf.h"
 #include "chrome/renderer/printing/print_web_view_helper.h"
-#include "chrome/renderer/tts_dispatcher.h"
 #include "content/public/common/content_constants.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/renderer/render_frame.h"
@@ -51,6 +50,10 @@
 #include "chrome/renderer/pepper/pepper_helper.h"
 #endif  // BUILDFLAG(ENABLE_PEPPER_FLASH)
 
+#if BUILDFLAG(ENABLE_TTS)
+#include "chrome/renderer/tts_dispatcher.h"
+#endif  // BUILDFLAG(ENABLE_TTS)
+
 namespace atom {
 
 namespace {
@@ -204,7 +207,11 @@ void RendererClientBase::DidClearWindowObject(
 std::unique_ptr<blink::WebSpeechSynthesizer>
 RendererClientBase::OverrideSpeechSynthesizer(
     blink::WebSpeechSynthesizerClient* client) {
+#if BUILDFLAG(ENABLE_TTS)
   return std::make_unique<TtsDispatcher>(client);
+#else
+  return nullptr;
+#endif
 }
 
 bool RendererClientBase::OverrideCreatePlugin(