VADisplayState::PostSandboxInitialization from ctor

This CL moves the call to static PostSandboxInitialization()
from its user, VASupportedProfiles ctor, to the Initialize()
method; this way we improve encapsulation and guarantee that
VADisplayState sandbox is correctly initialize in all possible
call stacks.

TEST=simplechrome on Soraka playing back VP9 videos, chrome://gpu
enumeration and chrome://media-internals OK.
Compile-ran video_decode_accelerator_unittest with the vp9 file
and looked ok too.

Bug: 778093

Cq-Include-Trybots: master.tryserver.chromium.android:android_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel
Change-Id: I960437bb36e2d2fdf43c33251394b76f84d2ea74
Reviewed-on: https://chromium-review.googlesource.com/784470Reviewed-by: Pawel Osciak <posciak@chromium.org>
Commit-Queue: Miguel Casas <mcasas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#519908}

media/gpu/vaapi_wrapper.cc

@@ -149,8 +149,6 @@ class VADisplayState {
 
   // Initialize static data before sandbox is enabled.
   static void PreSandboxInitialization();
-  // Returns false on init failure.
-  static bool PostSandboxInitialization();
 
   VADisplayState();
   ~VADisplayState() = delete;
@@ -165,6 +163,9 @@ class VADisplayState {
   void SetDrmFd(base::PlatformFile fd) { drm_fd_.reset(HANDLE_EINTR(dup(fd))); }
 
  private:
+  // Returns false on init failure.
+  static bool PostSandboxInitialization();
+
   // Protected by |va_lock_|.
   int refcount_;
 
@@ -231,6 +232,11 @@ VADisplayState::VADisplayState()
 
 bool VADisplayState::Initialize() {
   va_lock_.AssertAcquired();
+
+  static bool result = PostSandboxInitialization();
+  if (!result)
+    return false;
+
   if (refcount_++ > 0)
     return true;
 
@@ -411,10 +417,6 @@ VASupportedProfiles::VASupportedProfiles()
       report_error_to_uma_cb_(base::Bind(&base::DoNothing)) {
   static_assert(arraysize(supported_profiles_) == VaapiWrapper::kCodecModeMax,
                 "The array size of supported profile is incorrect.");
-
-  static bool result = VADisplayState::PostSandboxInitialization();
-  if (!result)
-    return;
   {
     base::AutoLock auto_lock(*va_lock_);
     if (!VADisplayState::Get()->Initialize())