[Android] Fix sign of integer literal in test

tools/android/heap_profiler/heap_profiler_unittest.cc

 // Copyright 2014 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 <stddef.h>
 #include <stdint.h>
 #include <string.h>
 #include <map>
 
 #include "testing/gtest/include/gtest/gtest.h"
@@ skipping 416 matching lines @@
 #ifdef __LP64__
 TEST_F(HeapProfilerTest, Test64Bit) {
   StackTrace st1 = GenStackTrace(8, 0x0);
   StackTrace st2 = GenStackTrace(10, 0x7fffffff70000000L);
   StackTrace st3 = GenStackTrace(10, 0xffffffff70000000L);
   heap_profiler_alloc((void*)0x1000, 4096, st1.frames, st1.depth, 0);
   heap_profiler_alloc(
       (void*)0x7ffffffffffff000L, 4096, st2.frames, st2.depth, 0);
   heap_profiler_alloc(
       (void*)0xfffffffffffff000L, 4096, st3.frames, st3.depth, 0);
-  EXPECT_EQ(3, stats_.num_allocs);
-  EXPECT_EQ(3, stats_.num_stack_traces);
+  EXPECT_EQ(3u, stats_.num_allocs);
+  EXPECT_EQ(3u, stats_.num_stack_traces);
   EXPECT_EQ(4096u + 4096 + 4096, stats_.total_alloc_bytes);
 
   heap_profiler_free((void*)0x1000, 4096, NULL);
   EXPECT_EQ(2u, stats_.num_allocs);
   EXPECT_EQ(2u, stats_.num_stack_traces);
   EXPECT_EQ(4096u + 4096, stats_.total_alloc_bytes);
 
   heap_profiler_free((void*)0x7ffffffffffff000L, 4096, NULL);
   EXPECT_EQ(1u, stats_.num_allocs);
   EXPECT_EQ(1u, stats_.num_stack_traces);
   EXPECT_EQ(4096u, stats_.total_alloc_bytes);
 
   heap_profiler_free((void*)0xfffffffffffff000L, 4096, NULL);
   EXPECT_EQ(0u, stats_.num_allocs);
   EXPECT_EQ(0u, stats_.num_stack_traces);
   EXPECT_EQ(0u, stats_.total_alloc_bytes);
 }
 #endif
 
 }  // namespace