Revert "Use OzonePlatform::InitParams everywhere."

This reverts commit e2c8d813.

Reason for revert: It breaks video_VideoDecodeAccelerator test on all
ChromeOS platforms.
https://bugs.chromium.org/p/chromium/issues/detail?id=744263

Original change's description:
> Use OzonePlatform::InitParams everywhere.
> 
> Remove the deprecated function that uses default InitParams. Add the
> params in the remaining callsites and set |single_process| correctly for
> tests. The only exception is in aura::Env::Init() where we don't know
> if it is a test.
> 
> Bug: 620934,700142
> Change-Id: I5e0d61578a423dd42eca38d21ccd1568b9ce5a8b
> Reviewed-on: https://chromium-review.googlesource.com/568361
> Reviewed-by: Scott Violet <sky@chromium.org>
> Reviewed-by: Robert Kroeger <rjkroege@chromium.org>
> Commit-Queue: kylechar <kylechar@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#486421}

TBR=rjkroege@chromium.org,sky@chromium.org,kylechar@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 620934, 700142
Change-Id: I30b11889c9b42ff85e2748d6f0839d3a8de8a7ad
Reviewed-on: https://chromium-review.googlesource.com/575787Reviewed-by: Wu-Cheng Li <wuchengli@chromium.org>
Commit-Queue: Hung-yu Wu <hywu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#487381}

media/gpu/video_decode_accelerator_unittest.cc

@@ -1851,9 +1851,7 @@ class VDATestSuite : public base::TestSuite {
                 new media::VideoDecodeAcceleratorTestEnvironment()));
 
 #if defined(USE_OZONE)
-    ui::OzonePlatform::InitParams params;
-    params.single_process = true;
-    ui::OzonePlatform::InitializeForUI(params);
+    ui::OzonePlatform::InitializeForUI();
 #endif
 
 #if defined(OS_CHROMEOS) && defined(ARCH_CPU_X86_FAMILY)

ui/aura/env.cc

@@ -174,11 +174,7 @@ void Env::Init() {
   // The ozone platform can provide its own event source. So initialize the
   // platform before creating the default event source. If running inside mus
   // let the mus process initialize ozone instead.
-  ui::OzonePlatform::InitParams params;
-  // TODO(kylechar): |params.single_process| should be set correctly here, but
-  // both tests and real code both use aura::Init::CreateInstance() identically.
-  params.single_process = false;
-  ui::OzonePlatform::InitializeForUI(params);
+  ui::OzonePlatform::InitializeForUI();
   gfx::ClientNativePixmapFactory::SetInstance(native_pixmap_factory_.get());
 #endif
   if (!ui::PlatformEventSource::GetInstance())

ui/compositor/test/test_suite.cc

@@ -35,9 +35,7 @@ void CompositorTestSuite::Initialize() {
   gl::GLSurfaceTestSupport::InitializeOneOff();
 
 #if defined(USE_OZONE)
-  ui::OzonePlatform::InitParams params;
-  params.single_process = true;
-  ui::OzonePlatform::InitializeForUI(params);
+  ui::OzonePlatform::InitializeForUI();
 #endif
 
   gfx::RegisterPathProvider();

ui/ozone/demo/ozone_demo.cc

@@ -354,9 +354,7 @@ int main(int argc, char** argv) {
   base::MessageLoopForUI message_loop;
   base::TaskScheduler::CreateAndStartWithDefaultParams("OzoneDemo");
 
-  ui::OzonePlatform::InitParams params;
-  params.single_process = true;
-  ui::OzonePlatform::InitializeForUI(params);
+  ui::OzonePlatform::InitializeForUI();
   ui::KeyboardLayoutEngineManager::GetKeyboardLayoutEngine()
       ->SetCurrentLayoutByName("us");
 

ui/ozone/public/ozone_platform.cc

@@ -31,6 +31,12 @@ OzonePlatform::~OzonePlatform() {
   instance_ = NULL;
 }
 
+// static
+void OzonePlatform::InitializeForUI() {
+  const InitParams params;
+  OzonePlatform::InitializeForUI(params);
+}
+
 // static
 void OzonePlatform::InitializeForUI(const InitParams& args) {
   EnsureInstance();

ui/ozone/public/ozone_platform.h

@@ -78,6 +78,11 @@ class OZONE_EXPORT OzonePlatform {
   // platform selected at runtime, e.g. ::GetMessageLoopTypeForGpu.
   static OzonePlatform* EnsureInstance();
 
+  // Initializes the subsystems/resources necessary for the UI process (e.g.
+  // events, etc.)
+  // TODO(rjkroege): Remove deprecated entry point (http://crbug.com/620934)
+  static void InitializeForUI();
+
   // Initializes the subsystems/resources necessary for the UI process (e.g.
   // events) with additional properties to customize the ozone platform
   // implementation. Ozone will not retain InitParams after returning from