Make PP_TimeTicks actually be a tick counter rather than be the same as the

wall clock time.

TEST=none
BUG=57448
Review URL: http://codereview.chromium.org/7237044

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@91860 0039d316-1c4b-4281-b951-d872f2087c98

13 files changed, 171 insertions, 34 deletions

diff --git a/webkit/glue/webkit_glue.gypi b/webkit/glue/webkit_glue.gypi
index ae8319d..8b0272e 100644
--- a/webkit/glue/webkit_glue.gypi
+++ b/webkit/glue/webkit_glue.gypi
@@ -310,6 +310,8 @@
         '../plugins/ppapi/resource_creation_impl.h',
         '../plugins/ppapi/resource_tracker.cc',
         '../plugins/ppapi/resource_tracker.h',
+        '../plugins/ppapi/time_conversion.cc',
+        '../plugins/ppapi/time_conversion.h',
         '../plugins/ppapi/string.cc',
         '../plugins/ppapi/string.h',
         '../plugins/ppapi/var.cc',
diff --git a/webkit/plugins/ppapi/event_conversion.cc b/webkit/plugins/ppapi/event_conversion.cc
index 5a05fd1..c0588e3 100644
--- a/webkit/plugins/ppapi/event_conversion.cc
+++ b/webkit/plugins/ppapi/event_conversion.cc
@@ -15,6 +15,7 @@
 #include "ppapi/shared_impl/input_event_impl.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebInputEvent.h"
 #include "webkit/plugins/ppapi/common.h"
+#include "webkit/plugins/ppapi/time_conversion.h"
 
 using ppapi::InputEventData;
 using WebKit::WebInputEvent;
@@ -63,10 +64,7 @@ PP_InputEvent_Type ConvertEventTypes(WebInputEvent::Type wetype) {
 InputEventData GetEventWithCommonFieldsAndType(const WebInputEvent& web_event) {
   InputEventData result;
   result.event_type = ConvertEventTypes(web_event.type);
-  // TODO(brettw) http://code.google.com/p/chromium/issues/detail?id=57448
-  // This should use a tick count rather than the wall clock time that WebKit
-  // uses.
-  result.event_time_stamp = web_event.timeStampSeconds;
+  result.event_time_stamp = EventTimeToPPTimeTicks(web_event.timeStampSeconds);
   return result;
 }
 
@@ -167,7 +165,7 @@ WebKeyboardEvent* BuildKeyEvent(const PP_InputEvent& event) {
     default:
       NOTREACHED();
   }
-  key_event->timeStampSeconds = event.time_stamp;
+  key_event->timeStampSeconds = PPTimeTicksToEventTime(event.time_stamp);
   key_event->modifiers = event.u.key.modifier;
   key_event->windowsKeyCode = event.u.key.key_code;
   return key_event;
@@ -176,7 +174,7 @@ WebKeyboardEvent* BuildKeyEvent(const PP_InputEvent& event) {
 WebKeyboardEvent* BuildCharEvent(const PP_InputEvent& event) {
   WebKeyboardEvent* key_event = new WebKeyboardEvent();
   key_event->type = WebInputEvent::Char;
-  key_event->timeStampSeconds = event.time_stamp;
+  key_event->timeStampSeconds = PPTimeTicksToEventTime(event.time_stamp);
   key_event->modifiers = event.u.character.modifier;
 
   // Make sure to not read beyond the buffer in case some bad code doesn't
@@ -220,7 +218,7 @@ WebMouseEvent* BuildMouseEvent(const PP_InputEvent& event) {
     default:
       NOTREACHED();
   }
-  mouse_event->timeStampSeconds = event.time_stamp;
+  mouse_event->timeStampSeconds = PPTimeTicksToEventTime(event.time_stamp);
   mouse_event->modifiers = event.u.mouse.modifier;
   mouse_event->button =
       static_cast<WebMouseEvent::Button>(event.u.mouse.button);
@@ -233,7 +231,8 @@ WebMouseEvent* BuildMouseEvent(const PP_InputEvent& event) {
 WebMouseWheelEvent* BuildMouseWheelEvent(const PP_InputEvent& event) {
   WebMouseWheelEvent* mouse_wheel_event = new WebMouseWheelEvent();
   mouse_wheel_event->type = WebInputEvent::MouseWheel;
-  mouse_wheel_event->timeStampSeconds = event.time_stamp;
+  mouse_wheel_event->timeStampSeconds =
+      PPTimeTicksToEventTime(event.time_stamp);
   mouse_wheel_event->modifiers = event.u.wheel.modifier;
   mouse_wheel_event->deltaX = event.u.wheel.delta_x;
   mouse_wheel_event->deltaY = event.u.wheel.delta_y;
diff --git a/webkit/plugins/ppapi/file_callbacks.cc b/webkit/plugins/ppapi/file_callbacks.cc
index de913f4..d7e00ea 100644
--- a/webkit/plugins/ppapi/file_callbacks.cc
+++ b/webkit/plugins/ppapi/file_callbacks.cc
@@ -14,6 +14,7 @@
 #include "webkit/plugins/ppapi/plugin_module.h"
 #include "webkit/plugins/ppapi/ppb_directory_reader_impl.h"
 #include "webkit/plugins/ppapi/ppb_file_system_impl.h"
+#include "webkit/plugins/ppapi/time_conversion.h"
 
 namespace webkit {
 namespace ppapi {
@@ -51,9 +52,9 @@ void FileCallbacks::DidReadMetadata(
   DCHECK(info_);
   DCHECK(file_system_);
   info_->size = file_info.size;
-  info_->creation_time = file_info.creation_time.ToDoubleT();
-  info_->last_access_time = file_info.last_accessed.ToDoubleT();
-  info_->last_modified_time = file_info.last_modified.ToDoubleT();
+  info_->creation_time = TimeToPPTime(file_info.creation_time);
+  info_->last_access_time = TimeToPPTime(file_info.last_accessed);
+  info_->last_modified_time = TimeToPPTime(file_info.last_modified);
   info_->system_type = file_system_->type();
   if (file_info.is_directory)
     info_->type = PP_FILETYPE_DIRECTORY;
diff --git a/webkit/plugins/ppapi/plugin_module.cc b/webkit/plugins/ppapi/plugin_module.cc
index 4fc1fd2..5daf60e 100644
--- a/webkit/plugins/ppapi/plugin_module.cc
+++ b/webkit/plugins/ppapi/plugin_module.cc
@@ -149,15 +149,12 @@ void MemFree(void* ptr) {
   free(ptr);
 }
 
-double GetTime() {
-  return base::Time::Now().ToDoubleT();
+PP_Time GetTime() {
+  return TimeToPPTime(base::Time::Now());
 }
 
-double GetTickTime() {
-  // TODO(brettw) http://code.google.com/p/chromium/issues/detail?id=57448
-  // This should be a tick timer rather than wall clock time, but needs to
-  // match message times, which also currently use wall clock time.
-  return GetTime();
+PP_TimeTicks GetTickTime() {
+  return TimeTicksToPPTimeTicks(base::TimeTicks::Now());
 }
 
 void CallOnMainThread(int delay_in_msec,
diff --git a/webkit/plugins/ppapi/plugin_module.h b/webkit/plugins/ppapi/plugin_module.h
index 52865bfc..e9bf1fe 100644
--- a/webkit/plugins/ppapi/plugin_module.h
+++ b/webkit/plugins/ppapi/plugin_module.h
@@ -21,6 +21,7 @@
 #include "ppapi/c/pp_module.h"
 #include "ppapi/c/ppb.h"
 #include "webkit/plugins/ppapi/plugin_delegate.h"
+#include "webkit/plugins/ppapi/time_conversion.h"
 
 class FilePath;
 class MessageLoop;
diff --git a/webkit/plugins/ppapi/ppb_file_io_impl.cc b/webkit/plugins/ppapi/ppb_file_io_impl.cc
index 1a19912..16a438a 100644
--- a/webkit/plugins/ppapi/ppb_file_io_impl.cc
+++ b/webkit/plugins/ppapi/ppb_file_io_impl.cc
@@ -23,6 +23,7 @@
 #include "webkit/plugins/ppapi/ppapi_plugin_instance.h"
 #include "webkit/plugins/ppapi/ppb_file_ref_impl.h"
 #include "webkit/plugins/ppapi/resource_tracker.h"
+#include "webkit/plugins/ppapi/time_conversion.h"
 
 using ppapi::thunk::EnterResourceNoLock;
 using ppapi::thunk::PPB_FileIO_API;
@@ -111,16 +112,16 @@ int32_t PPB_FileIO_Impl::Query(PP_FileInfo* info,
 }
 
 int32_t PPB_FileIO_Impl::Touch(PP_Time last_access_time,
-                      PP_Time last_modified_time,
-                      PP_CompletionCallback callback) {
+                               PP_Time last_modified_time,
+                               PP_CompletionCallback callback) {
   int32_t rv = CommonCallValidation(true, callback);
   if (rv != PP_OK)
     return rv;
 
   if (!base::FileUtilProxy::Touch(
           instance()->delegate()->GetFileThreadMessageLoopProxy(),
-          file_, base::Time::FromDoubleT(last_access_time),
-          base::Time::FromDoubleT(last_modified_time),
+          file_, PPTimeToTime(last_access_time),
+          PPTimeToTime(last_modified_time),
           callback_factory_.NewCallback(&PPB_FileIO_Impl::StatusCallback)))
     return PP_ERROR_FAILED;
 
@@ -285,9 +286,9 @@ void PPB_FileIO_Impl::QueryInfoCallback(
   DCHECK(info_);
   if (error_code == base::PLATFORM_FILE_OK) {
     info_->size = file_info.size;
-    info_->creation_time = file_info.creation_time.ToDoubleT();
-    info_->last_access_time = file_info.last_accessed.ToDoubleT();
-    info_->last_modified_time = file_info.last_modified.ToDoubleT();
+    info_->creation_time = TimeToPPTime(file_info.creation_time);
+    info_->last_access_time = TimeToPPTime(file_info.last_accessed);
+    info_->last_modified_time = TimeToPPTime(file_info.last_modified);
     info_->system_type = file_system_type_;
     if (file_info.is_directory)
       info_->type = PP_FILETYPE_DIRECTORY;
diff --git a/webkit/plugins/ppapi/ppb_file_ref_impl.cc b/webkit/plugins/ppapi/ppb_file_ref_impl.cc
index 207ebb1..547218e 100644
--- a/webkit/plugins/ppapi/ppb_file_ref_impl.cc
+++ b/webkit/plugins/ppapi/ppb_file_ref_impl.cc
@@ -17,6 +17,7 @@
 #include "webkit/plugins/ppapi/ppapi_plugin_instance.h"
 #include "webkit/plugins/ppapi/ppb_directory_reader_impl.h"
 #include "webkit/plugins/ppapi/ppb_file_system_impl.h"
+#include "webkit/plugins/ppapi/time_conversion.h"
 #include "webkit/plugins/ppapi/var.h"
 
 using ppapi::thunk::EnterResourceNoLock;
@@ -181,8 +182,8 @@ int32_t PPB_FileRef_Impl::Touch(PP_Time last_access_time,
     return PP_ERROR_NOACCESS;
   if (!instance()->delegate()->Touch(
           GetFileSystemURL(),
-          base::Time::FromDoubleT(last_access_time),
-          base::Time::FromDoubleT(last_modified_time),
+          PPTimeToTime(last_access_time),
+          PPTimeToTime(last_modified_time),
           new FileCallbacks(instance()->module()->AsWeakPtr(),
                             GetReferenceNoAddRef(), callback,
                             NULL, NULL, NULL)))
diff --git a/webkit/plugins/ppapi/ppb_flash_file_impl.cc b/webkit/plugins/ppapi/ppb_flash_file_impl.cc
index 297b9ee..3438cdb 100644
--- a/webkit/plugins/ppapi/ppb_flash_file_impl.cc
+++ b/webkit/plugins/ppapi/ppb_flash_file_impl.cc
@@ -20,6 +20,7 @@
 #include "webkit/plugins/ppapi/ppapi_plugin_instance.h"
 #include "webkit/plugins/ppapi/ppb_file_ref_impl.h"
 #include "webkit/plugins/ppapi/resource_tracker.h"
+#include "webkit/plugins/ppapi/time_conversion.h"
 
 #if defined(OS_WIN)
 #include "base/utf_string_conversions.h"
@@ -137,9 +138,9 @@ int32_t QueryModuleLocalFile(PP_Instance pp_instance,
       &file_info);
   if (result == base::PLATFORM_FILE_OK) {
     info->size = file_info.size;
-    info->creation_time = file_info.creation_time.ToDoubleT();
-    info->last_access_time = file_info.last_accessed.ToDoubleT();
-    info->last_modified_time = file_info.last_modified.ToDoubleT();
+    info->creation_time = TimeToPPTime(file_info.creation_time);
+    info->last_access_time = TimeToPPTime(file_info.last_accessed);
+    info->last_modified_time = TimeToPPTime(file_info.last_modified);
     info->system_type = PP_FILESYSTEMTYPE_EXTERNAL;
     if (file_info.is_directory)
       info->type = PP_FILETYPE_DIRECTORY;
@@ -253,9 +254,9 @@ int32_t QueryFileRefFile(PP_Resource file_ref_id,
       &file_info);
   if (result == base::PLATFORM_FILE_OK) {
     info->size = file_info.size;
-    info->creation_time = file_info.creation_time.ToDoubleT();
-    info->last_access_time = file_info.last_accessed.ToDoubleT();
-    info->last_modified_time = file_info.last_modified.ToDoubleT();
+    info->creation_time = TimeToPPTime(file_info.creation_time);
+    info->last_access_time = TimeToPPTime(file_info.last_accessed);
+    info->last_modified_time = TimeToPPTime(file_info.last_modified);
     info->system_type = PP_FILESYSTEMTYPE_EXTERNAL;
     if (file_info.is_directory)
       info->type = PP_FILETYPE_DIRECTORY;
diff --git a/webkit/plugins/ppapi/ppb_flash_impl.cc b/webkit/plugins/ppapi/ppb_flash_impl.cc
index 46f9cd91..bf537b5 100644
--- a/webkit/plugins/ppapi/ppb_flash_impl.cc
+++ b/webkit/plugins/ppapi/ppb_flash_impl.cc
@@ -17,6 +17,7 @@
 #include "webkit/plugins/ppapi/ppapi_plugin_instance.h"
 #include "webkit/plugins/ppapi/ppb_url_request_info_impl.h"
 #include "webkit/plugins/ppapi/resource_tracker.h"
+#include "webkit/plugins/ppapi/time_conversion.h"
 #include "webkit/plugins/ppapi/var.h"
 
 using ppapi::thunk::EnterResource;
@@ -95,7 +96,7 @@ double GetLocalTimeZoneOffset(PP_Instance pp_instance, PP_Time t) {
   // We can't do the conversion here because on Linux, the localtime calls
   // require filesystem access prohibited by the sandbox.
   return instance->delegate()->GetLocalTimeZoneOffset(
-      base::Time::FromDoubleT(t));
+      PPTimeToTime(t));
 }
 
 PP_Var GetCommandLineArgs(PP_Module pp_module) {
diff --git a/webkit/plugins/ppapi/time_conversion.cc b/webkit/plugins/ppapi/time_conversion.cc
new file mode 100644
index 0000000..d5f1282
--- /dev/null
+++ b/webkit/plugins/ppapi/time_conversion.cc
@@ -0,0 +1,51 @@
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "webkit/plugins/ppapi/time_conversion.h"
+
+namespace webkit {
+namespace ppapi {
+
+namespace {
+
+// Since WebKit doesn't use ticks for event times, we have to compute what
+// the time ticks would be assuming the wall clock time doesn't change.
+//
+// This should only be used for WebKit times which we can't change the
+// definition of.
+double GetTimeToTimeTicksDeltaInSeconds() {
+  static double time_to_ticks_delta_seconds = 0.0;
+  if (time_to_ticks_delta_seconds == 0.0) {
+    double wall_clock = TimeToPPTime(base::Time::Now());
+    double ticks = TimeTicksToPPTimeTicks(base::TimeTicks::Now());
+    time_to_ticks_delta_seconds = ticks - wall_clock;
+  }
+  return time_to_ticks_delta_seconds;
+}
+
+}  // namespace
+
+PP_Time TimeToPPTime(base::Time t) {
+  return t.ToDoubleT();
+}
+
+base::Time PPTimeToTime(PP_Time t) {
+  return base::Time::FromDoubleT(t);
+}
+
+PP_TimeTicks TimeTicksToPPTimeTicks(base::TimeTicks t) {
+  return static_cast<double>(t.ToInternalValue() /
+                             base::Time::kMicrosecondsPerSecond);
+}
+
+PP_TimeTicks EventTimeToPPTimeTicks(double event_time) {
+  return event_time + GetTimeToTimeTicksDeltaInSeconds();
+}
+
+double PPTimeTicksToEventTime(PP_TimeTicks t) {
+  return t - GetTimeToTimeTicksDeltaInSeconds();
+}
+
+}  // namespace ppapi
+}  // namespace webkit
diff --git a/webkit/plugins/ppapi/time_conversion.h b/webkit/plugins/ppapi/time_conversion.h
new file mode 100644
index 0000000..13050e4
--- /dev/null
+++ b/webkit/plugins/ppapi/time_conversion.h
@@ -0,0 +1,29 @@
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef WEBKIT_PLUGINS_PPAPI_TIME_CONVERSION_H_
+#define WEBKIT_PLUGINS_PPAPI_TIME_CONVERSION_H_
+
+#include "base/time.h"
+#include "ppapi/c/pp_time.h"
+
+namespace webkit {
+namespace ppapi {
+
+PP_Time TimeToPPTime(base::Time t);
+base::Time PPTimeToTime(PP_Time t);
+
+PP_TimeTicks TimeTicksToPPTimeTicks(base::TimeTicks t);
+
+// Converts between WebKit event times and time ticks. WebKit event times are
+// currently expressed in terms of wall clock time. This function does the
+// proper mapping to time ticks, assuming the wall clock time doesn't change
+// (which isn't necessarily the case).
+PP_TimeTicks EventTimeToPPTimeTicks(double event_time);
+double PPTimeTicksToEventTime(PP_TimeTicks t);
+
+}  // namespace ppapi
+}  // namespace webkit
+
+#endif  // WEBKIT_PLUGINS_PPAPI_TIME_CONVERSION_H_
diff --git a/webkit/plugins/ppapi/time_conversion_unittest.cc b/webkit/plugins/ppapi/time_conversion_unittest.cc
new file mode 100644
index 0000000..50fc116
--- /dev/null
+++ b/webkit/plugins/ppapi/time_conversion_unittest.cc
@@ -0,0 +1,52 @@
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <math.h>
+#include <stdlib.h>
+
+#include "testing/gtest/include/gtest/gtest.h"
+#include "webkit/plugins/ppapi/time_conversion.h"
+
+namespace webkit {
+namespace ppapi {
+
+// Slop we'll allow in two Time "internal values" to consider them equal.
+// Double conversion can introduce rounding errors. The internal values are in
+// microseconds, so an error here is very small.
+static const int kTimeInternalValueSlop = 2;
+
+// Same as above in double-precision seconds units.
+static const double kTimeSecondsSlop =
+    static_cast<double>(kTimeInternalValueSlop) /
+    base::Time::kMicrosecondsPerSecond;
+
+TEST(TimeConversion, Time) {
+  // Should be able to round-trip.
+  base::Time now = base::Time::Now();
+  base::Time converted = PPTimeToTime(TimeToPPTime(now));
+  EXPECT_GE(kTimeInternalValueSlop,
+            abs(static_cast<int>((converted - now).ToInternalValue())));
+
+  // Units should be in seconds.
+  base::Time one_second_from_now = now + base::TimeDelta::FromSeconds(1);
+  EXPECT_EQ(1.0, TimeToPPTime(one_second_from_now) - TimeToPPTime(now));
+}
+
+TEST(TimeConversion, EventTime) {
+  // Should be able to round-trip.
+  base::Time now = base::Time::Now();
+  double event_now = now.ToDoubleT();
+  double converted = EventTimeToPPTimeTicks(PPTimeTicksToEventTime(event_now));
+  EXPECT_GE(kTimeSecondsSlop, fabs(converted - event_now));
+
+  // Units should be in seconds.
+  base::Time one_second_from_now = now + base::TimeDelta::FromSeconds(1);
+  double event_one_second_from_now = one_second_from_now.ToDoubleT();
+  EXPECT_GE(kTimeSecondsSlop,
+            1.0 - EventTimeToPPTimeTicks(event_one_second_from_now) -
+                EventTimeToPPTimeTicks(event_now));
+}
+
+}  // namespace ppapi
+}  // namespace webkit
diff --git a/webkit/tools/test_shell/test_shell.gypi b/webkit/tools/test_shell/test_shell.gypi
index d6b335f..99eb955 100644
--- a/webkit/tools/test_shell/test_shell.gypi
+++ b/webkit/tools/test_shell/test_shell.gypi
@@ -442,6 +442,7 @@
         '../../plugins/ppapi/ppapi_unittest.cc',
         '../../plugins/ppapi/ppapi_unittest.h',
         '../../plugins/ppapi/resource_tracker_unittest.cc',
+        '../../plugins/ppapi/time_conversion_unittest.cc',
         '../../plugins/ppapi/url_request_info_unittest.cc',
         '../../quota/mock_special_storage_policy.cc',
         '../../quota/mock_special_storage_policy.h',