Reland of place basictypes.h with stdint.h for int_t types. (patchset #1 id:1 of https://codereview.webrtc.org/2603203003/ )

Reason for revert:
Doing a reland where systeminfo.cc includes basictypes.h so that CPU_X86 etc. are defined when they are checked/used.

Original issue's description:
> Revert of Replace basictypes.h with stdint.h for int_t types. (patchset #1 id:1 of https://codereview.webrtc.org/2604043002/ )
>
> Reason for revert:
> Very likely cause of Chromium import bot breakage (unused function '__cpuid'), TBD why.
>
> Original issue's description:
> > Replace basictypes.h with stdint.h for int_t types.
> >
> > Removes basictypes.h for types that only makes use of it for fixed-size-int
> > typedefs and replaces it with stdint.h.
> >
> > BUG=webrtc:6853
> > R=tommi@webrtc.org
> >
> > Review-Url: https://codereview.webrtc.org/2604043002
> > Cr-Commit-Position: refs/heads/master@{#15867}
> > Committed: https://chromium.googlesource.com/external/webrtc/+/7fd1a753005ca93e8bd934a55808a2137b0ad84f
>
> TBR=tommi@webrtc.org
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=webrtc:6853
>
> Review-Url: https://codereview.webrtc.org/2603203003
> Cr-Commit-Position: refs/heads/master@{#15869}
> Committed: https://chromium.googlesource.com/external/webrtc/+/7eb0e23bcf675635ef339a519a10563ebc9d93dc

BUG=webrtc:6853
TBR=tommi@webrtc.org

Review-Url: https://codereview.webrtc.org/2609783002
Cr-Commit-Position: refs/heads/master@{#15873}
diff --git a/webrtc/modules/rtp_rtcp/source/playout_delay_oracle.h b/webrtc/modules/rtp_rtcp/source/playout_delay_oracle.h
index f4cbe52..013d1c1 100644
--- a/webrtc/modules/rtp_rtcp/source/playout_delay_oracle.h
+++ b/webrtc/modules/rtp_rtcp/source/playout_delay_oracle.h
@@ -11,7 +11,8 @@
 #ifndef WEBRTC_MODULES_RTP_RTCP_SOURCE_PLAYOUT_DELAY_ORACLE_H_
 #define WEBRTC_MODULES_RTP_RTCP_SOURCE_PLAYOUT_DELAY_ORACLE_H_
 
-#include "webrtc/base/basictypes.h"
+#include <stdint.h>
+
 #include "webrtc/base/criticalsection.h"
 #include "webrtc/base/thread_annotations.h"
 #include "webrtc/modules/include/module_common_types.h"
diff --git a/webrtc/modules/rtp_rtcp/source/rtp_header_extensions.h b/webrtc/modules/rtp_rtcp/source/rtp_header_extensions.h
index afe47e5..56e4c15 100644
--- a/webrtc/modules/rtp_rtcp/source/rtp_header_extensions.h
+++ b/webrtc/modules/rtp_rtcp/source/rtp_header_extensions.h
@@ -10,7 +10,8 @@
 #ifndef WEBRTC_MODULES_RTP_RTCP_SOURCE_RTP_HEADER_EXTENSIONS_H_
 #define WEBRTC_MODULES_RTP_RTCP_SOURCE_RTP_HEADER_EXTENSIONS_H_
 
-#include "webrtc/base/basictypes.h"
+#include <stdint.h>
+
 #include "webrtc/common_video/rotation.h"
 #include "webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h"
 
diff --git a/webrtc/modules/rtp_rtcp/source/time_util.h b/webrtc/modules/rtp_rtcp/source/time_util.h
index 5a9525a..7bac526 100644
--- a/webrtc/modules/rtp_rtcp/source/time_util.h
+++ b/webrtc/modules/rtp_rtcp/source/time_util.h
@@ -11,7 +11,8 @@
 #ifndef WEBRTC_MODULES_RTP_RTCP_SOURCE_TIME_UTIL_H_
 #define WEBRTC_MODULES_RTP_RTCP_SOURCE_TIME_UTIL_H_
 
-#include "webrtc/base/basictypes.h"
+#include <stdint.h>
+
 #include "webrtc/system_wrappers/include/ntp_time.h"
 
 namespace webrtc {
diff --git a/webrtc/modules/video_coding/h264_sprop_parameter_sets_unittest.cc b/webrtc/modules/video_coding/h264_sprop_parameter_sets_unittest.cc
index 29b6617..6455670 100644
--- a/webrtc/modules/video_coding/h264_sprop_parameter_sets_unittest.cc
+++ b/webrtc/modules/video_coding/h264_sprop_parameter_sets_unittest.cc
@@ -10,8 +10,10 @@
 
 #include "webrtc/modules/video_coding/h264_sprop_parameter_sets.h"
 
+#include <stdint.h>
+
 #include <vector>
-#include "webrtc/base/basictypes.h"
+
 #include "webrtc/test/gtest.h"
 
 namespace webrtc {
diff --git a/webrtc/modules/video_coding/utility/default_video_bitrate_allocator.cc b/webrtc/modules/video_coding/utility/default_video_bitrate_allocator.cc
index cb701f2..482c8ec 100644
--- a/webrtc/modules/video_coding/utility/default_video_bitrate_allocator.cc
+++ b/webrtc/modules/video_coding/utility/default_video_bitrate_allocator.cc
@@ -9,8 +9,8 @@
  */
 
 #include "webrtc/modules/video_coding/utility/default_video_bitrate_allocator.h"
-#include "webrtc/base/basictypes.h"
-#include "webrtc/base/constructormagic.h"
+
+#include <stdint.h>
 
 namespace webrtc {
 
diff --git a/webrtc/modules/video_coding/utility/simulcast_rate_allocator.h b/webrtc/modules/video_coding/utility/simulcast_rate_allocator.h
index 149e866..7f54f5c 100644
--- a/webrtc/modules/video_coding/utility/simulcast_rate_allocator.h
+++ b/webrtc/modules/video_coding/utility/simulcast_rate_allocator.h
@@ -11,10 +11,11 @@
 #ifndef WEBRTC_MODULES_VIDEO_CODING_UTILITY_SIMULCAST_RATE_ALLOCATOR_H_
 #define WEBRTC_MODULES_VIDEO_CODING_UTILITY_SIMULCAST_RATE_ALLOCATOR_H_
 
+#include <stdint.h>
+
 #include <map>
 #include <memory>
 
-#include "webrtc/base/basictypes.h"
 #include "webrtc/base/constructormagic.h"
 #include "webrtc/common_video/include/video_bitrate_allocator.h"
 #include "webrtc/modules/video_coding/codecs/vp8/temporal_layers.h"