Fuchsia: stub out missing ProcessMetrics methods.

Fuchsia: stub out missing ProcessMetrics methods.
The absence of Fuchsia stubs for these methods produced linker errors
when compiling the headless shell.

R: scottmg@chromium.org
Bug: 750948
Change-Id: If9e13e80e17852fe7692164b2cd0c728bdded9f3
Reviewed-on: https://chromium-review.googlesource.com/596624
Commit-Queue: Kevin Marshall <kmarshall@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#491799}

base/message_loop/message_loop.cc

@@ -625,7 +625,8 @@ void MessageLoopForUI::Attach() {
 }
 #endif
 
-#if defined(USE_OZONE) || (defined(USE_X11) && !defined(USE_GLIB))
+#if (defined(USE_OZONE) && !defined(OS_FUCHSIA)) || \
+    (defined(USE_X11) && !defined(USE_GLIB))
 bool MessageLoopForUI::WatchFileDescriptor(
     int fd,
     bool persistent,

base/message_loop/message_loop.h

@@ -497,7 +497,8 @@ class BASE_EXPORT MessageLoopForUI : public MessageLoop {
   void Abort();
 #endif
 
-#if defined(USE_OZONE) || (defined(USE_X11) && !defined(USE_GLIB))
+#if (defined(USE_OZONE) && !defined(OS_FUCHSIA)) || \
+    (defined(USE_X11) && !defined(USE_GLIB))
   // Please see MessagePumpLibevent for definition.
   bool WatchFileDescriptor(
       int fd,

base/process/process_metrics_fuchsia.cc

@@ -15,15 +15,28 @@ size_t GetSystemCommitCharge() {
 // static
 std::unique_ptr<ProcessMetrics> ProcessMetrics::CreateProcessMetrics(
     ProcessHandle process) {
-  // TODO(fuchsia): Not currently implementable. May eventually be for the
-  // current process. https://crbug.com/706592.
+  NOTIMPLEMENTED();  // TODO(fuchsia): https://crbug.com/706592.
   return nullptr;
 }
 
 double ProcessMetrics::GetCPUUsage() {
-  // TODO(fuchsia): Not current implementable. May eventually be for the current
-  // process. https://crbug.com/706592.
+  NOTIMPLEMENTED();  // TODO(fuchsia): https://crbug.com/706592.
   return 0.0;
 }
 
+size_t ProcessMetrics::GetPagefileUsage() const {
+  NOTIMPLEMENTED();  // TODO(fuchsia): https://crbug.com/706592.
+  return 0;
+}
+
+size_t ProcessMetrics::GetWorkingSetSize() const {
+  NOTIMPLEMENTED();  // TODO(fuchsia): https://crbug.com/706592.
+  return 0;
+}
+
+size_t ProcessMetrics::GetPeakWorkingSetSize() const {
+  NOTIMPLEMENTED();  // TODO(fuchsia): https://crbug.com/706592.
+  return 0;
+}
+
 }  // namespace base

build/args/fuchsia.gn

+import("//build/args/headless.gn")
+
+target_os = "fuchsia"
+enable_basic_printing = false
+enable_webrtc = false
+headless_fontconfig_utils = false
+toolkit_views = false
+enable_plugins = false