Deletes the now-unused addTrace methods that don't accept user-supplied timestamps.

Follow-up to http://crrev.com/870053006 (which added the methods that accept user-supplied timestamps) and http://crrev.com/892463004 (which modified Blink to use the user-supplied timestamps).

BUG=345845

Review URL: https://codereview.chromium.org/894913006

Cr-Commit-Position: refs/heads/master@{#315215}

content/child/blink_platform_impl.cc

@@ -666,38 +666,6 @@ blink::Platform::TraceEventHandle BlinkPlatformImpl::addTraceEvent(
   return result;
 }
 
-blink::Platform::TraceEventHandle BlinkPlatformImpl::addTraceEvent(
-    char phase,
-    const unsigned char* category_group_enabled,
-    const char* name,
-    unsigned long long id,
-    int num_args,
-    const char** arg_names,
-    const unsigned char* arg_types,
-    const unsigned long long* arg_values,
-    unsigned char flags) {
-  return addTraceEvent(phase, category_group_enabled, name, id,
-                       monotonicallyIncreasingTime(),
-                       num_args, arg_names, arg_types, arg_values, flags);
-}
-
-blink::Platform::TraceEventHandle BlinkPlatformImpl::addTraceEvent(
-    char phase,
-    const unsigned char* category_group_enabled,
-    const char* name,
-    unsigned long long id,
-    int num_args,
-    const char** arg_names,
-    const unsigned char* arg_types,
-    const unsigned long long* arg_values,
-    const blink::WebConvertableToTraceFormat* convertable_values,
-    unsigned char flags) {
-  return addTraceEvent(phase, category_group_enabled, name, id,
-                       monotonicallyIncreasingTime(),
-                       num_args, arg_names, arg_types, arg_values,
-                       convertable_values, flags);
-}
-
 void BlinkPlatformImpl::updateTraceEventDuration(
     const unsigned char* category_group_enabled,
     const char* name,

content/child/blink_platform_impl.h

@@ -122,29 +122,6 @@ class CONTENT_EXPORT BlinkPlatformImpl
       const unsigned long long* arg_values,
       const blink::WebConvertableToTraceFormat* convertable_values,
       unsigned char flags);
-  // TODO(charliea): Remove the addTraceEvent methods without timestamps
-  // once Blink uses the new signature with timestamps
-  virtual TraceEventHandle addTraceEvent(
-      char phase,
-      const unsigned char* category_group_enabled,
-      const char* name,
-      unsigned long long id,
-      int num_args,
-      const char** arg_names,
-      const unsigned char* arg_types,
-      const unsigned long long* arg_values,
-      unsigned char flags);
-  virtual TraceEventHandle addTraceEvent(
-      char phase,
-      const unsigned char* category_group_enabled,
-      const char* name,
-      unsigned long long id,
-      int num_args,
-      const char** arg_names,
-      const unsigned char* arg_types,
-      const unsigned long long* arg_values,
-      const blink::WebConvertableToTraceFormat* convertable_values,
-      unsigned char flags);
   virtual void updateTraceEventDuration(
       const unsigned char* category_group_enabled,
       const char* name,