Revert "Alias 4KB at the beginning of JSONParser::ConsumeDictionary() to help...

Revert "Alias 4KB at the beginning of JSONParser::ConsumeDictionary() to help diagnose issue 791487."

This reverts commit f09eb6cc.

Reason for revert: diagnosis of issue complete.

Original change's description:
> Alias 4KB at the beginning of JSONParser::ConsumeDictionary() to help diagnose issue 791487.
> 
> R=​siggi@chromium.org
> 
> Bug: 791487
> Change-Id: I4535df5a52167f2f5b10424a07e035e1c46e8cfb
> Reviewed-on: https://chromium-review.googlesource.com/850722
> Commit-Queue: Gabriel Charette <gab@chromium.org>
> Reviewed-by: Sigurður Ásgeirsson <siggi@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#527154}

TBR=gab@chromium.org,siggi@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 791487
Change-Id: Ic9dff2009411498a97ba3c1e488254414659a5ef
Reviewed-on: https://chromium-review.googlesource.com/1059735Reviewed-by: Sigurður Ásgeirsson <siggi@chromium.org>
Reviewed-by: Gabriel Charette <gab@chromium.org>
Commit-Queue: Gabriel Charette <gab@chromium.org>
Cr-Commit-Position: refs/heads/master@{#558881}

base/json/json_parser.cc

@@ -8,7 +8,6 @@
 #include <utility>
 #include <vector>
 
-#include "base/debug/alias.h"
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/numerics/safe_conversions.h"
@@ -327,16 +326,6 @@ Optional<Value> JSONParser::ParseToken(Token token) {
 }
 
 Optional<Value> JSONParser::ConsumeDictionary() {
-  // Attempt to alias 4KB of the buffer about to be read. Need to alias multiple
-  // sites as the crashpad heuristics only grab a few hundred bytes in
-  // front/behind heap pointers on the stack.
-  // TODO(gab): Remove this after diagnosis of https://crbug.com/791487 is
-  // complete.
-  const char* initial_pos[16];
-  for (size_t i = 0; i < arraysize(initial_pos); ++i)
-    initial_pos[i] = pos() + i * 256;
-  debug::Alias(&initial_pos);
-
   if (ConsumeChar() != '{') {
     ReportError(JSONReader::JSON_UNEXPECTED_TOKEN, 1);
     return nullopt;