GWP-ASan: Add plain "enable_gwp_asan" buildflag

Previously GWP-ASan only exposed separate flags for whether it was
enabled for a given allocator. Create a convenience buildflag for places
when we need to check whether GWP-ASan is enabled for any allocator and
use it where appropriate.

Bug: 973167
Change-Id: I76f8ee2c258279ebd07e3b6f72651498358a95da
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1671866
Auto-Submit: Vlad Tsyrklevich <vtsyrklevich@chromium.org>
Reviewed-by: Vitaly Buka <vitalybuka@chromium.org>
Reviewed-by: Marc Treib <treib@chromium.org>
Commit-Queue: Vlad Tsyrklevich <vtsyrklevich@chromium.org>
Cr-Commit-Position: refs/heads/master@{#672200}

chrome/BUILD.gn

@@ -1487,7 +1487,7 @@ group("browser_dependencies") {
     }
   }
 
-  if (enable_gwp_asan_malloc || enable_gwp_asan_partitionalloc) {
+  if (enable_gwp_asan) {
     public_deps += [ "//components/gwp_asan/client" ]
   }
 
@@ -1532,7 +1532,7 @@ group("child_dependencies") {
     public_deps += [ "//components/nacl/renderer/plugin:nacl_trusted_plugin" ]
   }
 
-  if (enable_gwp_asan_malloc || enable_gwp_asan_partitionalloc) {
+  if (enable_gwp_asan) {
     public_deps += [ "//components/gwp_asan/client" ]
   }
 
@@ -1886,7 +1886,7 @@ if (is_android) {
       deps += [ "//third_party/gvr-android-sdk:gvr_shim" ]
     }
 
-    if (enable_gwp_asan_malloc || enable_gwp_asan_partitionalloc) {
+    if (enable_gwp_asan) {
       deps += [ "//components/gwp_asan/client" ]
     }
   }

chrome/app/BUILD.gn

@@ -395,7 +395,7 @@ static_library("test_support") {
     ]
   }
 
-  if (enable_gwp_asan_malloc || enable_gwp_asan_partitionalloc) {
+  if (enable_gwp_asan) {
     deps += [ "//components/gwp_asan/client" ]
   }
 }

chrome/app/chrome_main_delegate.cc

@@ -167,8 +167,7 @@
 #include "chrome/child/pdf_child_init.h"
 #endif
 
-#if BUILDFLAG(ENABLE_GWP_ASAN_MALLOC) || \
-    BUILDFLAG(ENABLE_GWP_ASAN_PARTITIONALLOC)
+#if BUILDFLAG(ENABLE_GWP_ASAN)
 #include "components/gwp_asan/client/gwp_asan.h"  // nogncheck
 #endif
 

components/gwp_asan/buildflags/BUILD.gn

@@ -10,5 +10,6 @@ buildflag_header("buildflags") {
   flags = [
     "ENABLE_GWP_ASAN_MALLOC=$enable_gwp_asan_malloc",
     "ENABLE_GWP_ASAN_PARTITIONALLOC=$enable_gwp_asan_partitionalloc",
+    "ENABLE_GWP_ASAN=$enable_gwp_asan",
   ]
 }

components/gwp_asan/buildflags/buildflags.gni

@@ -10,3 +10,8 @@ declare_args() {
   enable_gwp_asan_malloc = (is_win || is_mac) && use_allocator_shim
   enable_gwp_asan_partitionalloc = (is_win || is_mac) && use_partition_alloc
 }
+
+declare_args() {
+  # Convenience definition
+  enable_gwp_asan = enable_gwp_asan_malloc || enable_gwp_asan_partitionalloc
+}