[TimeZoneMonitor] Decouple renderer side impl from content to blink.

third_party/WebKit/Source/platform/exported/Platform.cpp

Index: third_party/WebKit/Source/platform/exported/Platform.cpp
diff --git a/third_party/WebKit/Source/platform/exported/Platform.cpp b/third_party/WebKit/Source/platform/exported/Platform.cpp
index 5d6d4f918409ec4f46a0eca145f1fdc2d1ec9f31..fc5c6c895c5ed2c43f89305ae6d3c2c167e777cc 100644
--- a/third_party/WebKit/Source/platform/exported/Platform.cpp
+++ b/third_party/WebKit/Source/platform/exported/Platform.cpp
@@ -28,6 +28,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include "base/message_loop/message_loop.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/trace_event/memory_dump_manager.h"
 #include "platform/Histogram.h"
@@ -141,6 +142,10 @@ Platform* Platform::current() {
   return s_platform;
 }
 
+bool Platform::isMessageLoopReady() {
+  return base::MessageLoop::current();
+}
+
 WebThread* Platform::mainThread() const {
   return m_mainThread;
 }