ozone: Initialize a subsystem only if necessary.

ui/ozone/ozone_platform.cc

Index: ui/ozone/ozone_platform.cc
diff --git a/ui/ozone/ozone_platform.cc b/ui/ozone/ozone_platform.cc
index e8199b2ce93f86846235f73b8459b9f650859d5f..281a7516fc1b45d065b7acac48bf86644e6fbaaa 100644
--- a/ui/ozone/ozone_platform.cc
+++ b/ui/ozone/ozone_platform.cc
@@ -18,11 +18,14 @@ namespace ui {
 namespace {
 
 // Helper to construct an OzonePlatform by name using the platform list.
-OzonePlatform* CreatePlatform(const std::string& platform_name) {
+OzonePlatform* CreatePlatform(const std::string& platform_name,
+                              bool for_gpu) {
   // Search for a matching platform in the list.
   for (int i = 0; i < kOzonePlatformCount; ++i)
-    if (platform_name == kOzonePlatforms[i].name)
-      return kOzonePlatforms[i].constructor();
+    if (platform_name == kOzonePlatforms[i].name) {
+      return for_gpu ? kOzonePlatforms[i].ConstructorForGPU()
+                     : kOzonePlatforms[i].ConstructorForUI();
+    }
 
   LOG(FATAL) << "Invalid ozone platform: " << platform_name;
   return NULL;  // not reached
@@ -40,31 +43,37 @@ std::string GetPlatformName() {
 
 }  // namespace
 
-OzonePlatform::OzonePlatform() {}
+OzonePlatform::OzonePlatform() {
+  CHECK(!instance_) << "There should only be a single OzonePlatform.";
+  instance_ = this;
+}
 
 OzonePlatform::~OzonePlatform() {
-  gfx::SurfaceFactoryOzone::SetInstance(NULL);
-  ui::EventFactoryOzone::SetInstance(NULL);
-  ui::CursorFactoryOzone::SetInstance(NULL);
+  CHECK_EQ(instance_, this);
+  instance_ = NULL;
 }
 
 // static
-void OzonePlatform::Initialize() {
+void OzonePlatform::InitializeForUI() {
   if (instance_)
     return;
 
   std::string platform = GetPlatformName();
-
-  TRACE_EVENT1("ozone", "OzonePlatform::Initialize", "platform", platform);
-
-  instance_ = CreatePlatform(platform);
-
-  // Inject ozone interfaces.
-  gfx::SurfaceFactoryOzone::SetInstance(instance_->GetSurfaceFactoryOzone());
-  ui::EventFactoryOzone::SetInstance(instance_->GetEventFactoryOzone());
+  TRACE_EVENT1("ozone", "OzonePlatform::InitializeForUI", "platform", platform);
+  CreatePlatform(platform, false);
   ui::InputMethodContextFactoryOzone::SetInstance(

[kalyank, 2014/05/15 19:21:45]

shouldn't we do the same with this. It should be set only in case of UI ?

[sadrul, 2014/05/15 19:27:24]

I wanted to, but the SetInstance() here is for the non-ozone
LinuxInputMethodContextFactory. So I left that alone for the moment. I do want
to revisit this soon though (I am not convinced we actually need the
InputMethodContextFactoryOzone at all. The ozone platforms should just
create/set a LinuxInputMethodContextFactory instance, and that should be
sufficient).

       instance_->GetInputMethodContextFactoryOzone());
-  ui::CursorFactoryOzone::SetInstance(instance_->GetCursorFactoryOzone());
+}
+
+// static
+void OzonePlatform::InitializeForGPU() {
+  if (instance_)
+    return;
+
+  std::string platform = GetPlatformName();
+  TRACE_EVENT1("ozone", "OzonePlatform::InitializeForGPU",
+               "platform", platform);
+  CreatePlatform(platform, true);
 }
 
 // static