A64: Synchronize with r17441.

build/toolchain.gypi

Index: build/toolchain.gypi
diff --git a/build/toolchain.gypi b/build/toolchain.gypi
index 82c6b7d7b52410be208e5c13901b7741506ed75f..6d0eddd509e58dcf318f10ada1b70039689a158a 100644
--- a/build/toolchain.gypi
+++ b/build/toolchain.gypi
@@ -60,20 +60,6 @@
 
     'v8_enable_backtrace%': 0,
 
-    # Speeds up Debug builds:
-    # 0 - Compiler optimizations off (debuggable) (default). This may
-    #     be 5x slower than Release (or worse).
-    # 1 - Turn on compiler optimizations. This may be hard or impossible to
-    #     debug. This may still be 2x slower than Release (or worse).
-    # 2 - Turn on optimizations, and also #undef DEBUG / #define NDEBUG
-    #     (but leave V8_ENABLE_CHECKS and most other assertions enabled.
-    #     This may cause some v8 tests to fail in the Debug configuration.
-    #     This roughly matches the performance of a Release build and can
-    #     be used by embedders that need to build their own code as debug
-    #     but don't want or need a debug version of V8. This should produce
-    #     near-release speeds.
-    'v8_optimized_debug%': 0,
-
     # Enable profiling support. Only required on Windows.
     'v8_enable_prof%': 0,
 
@@ -456,6 +442,7 @@
           'V8_ENABLE_CHECKS',
           'OBJECT_PRINT',
           'VERIFY_HEAP',
+          'DEBUG'
         ],
         'msvs_settings': {
           'VCCLCompilerTool': {
@@ -523,15 +510,6 @@
           },
         },
         'conditions': [
-          ['v8_optimized_debug==2', {
-            'defines': [
-              'NDEBUG',
-            ],
-          }, {
-            'defines': [
-              'DEBUG',
-            ],
-          }],
           ['OS=="linux" or OS=="freebsd" or OS=="openbsd" or OS=="netbsd"', {
             'cflags': [ '-Wall', '<(werror)', '-W', '-Wno-unused-parameter',
                         '-Wnon-virtual-dtor', '-Woverloaded-virtual',
@@ -577,6 +555,9 @@
                   '-fdata-sections',
                   '-ffunction-sections',
                 ],
+                'defines': [
+                  'OPTIMIZED_DEBUG'
+                ],
                 'conditions': [
                   # TODO(crbug.com/272548): Avoid -O3 in NaCl
                   ['nacl_target_arch=="none"', {