aura: Sanitize the lifetime of aura::Env instance.

Currently, the aura::Env instance is created and/or destroyed from unexpected
places (e.g. WebContentsViewAura), and that makes it difficult to reason about
its lifetime. This patch tries to make this better. Notable changes:

. Instead of having the ash::Shell instance be responsible for creating the
  aura::Env instance, make the creator of the Shell instance be responsible for
  also creating the aura::Env instance.
. Individual TestSuite instances are responsible for managing the aura::Env
  instance for the tests (content::UnitTestTestSuite, ash::AuraShellTestSuite)
. For chrome and browser-tests, the browser main-loop is responsible for
  managing the aura::Env instance.
. For interactive-ui-tests that do not use the browser main-loop, each test
  explicitly manages its aura::Env instance.

BUG=515031, 516898
TBR=avi@ for trivial change in content/browser/

Review URL: https://codereview.chromium.org/1270173004

Cr-Commit-Position: refs/heads/master@{#342300}

6 files changed, 21 insertions, 3 deletions

diff --git a/ash/accelerators/accelerator_interactive_uitest_chromeos.cc b/ash/accelerators/accelerator_interactive_uitest_chromeos.cc
index a776229..3babbc5 100644
--- a/ash/accelerators/accelerator_interactive_uitest_chromeos.cc
+++ b/ash/accelerators/accelerator_interactive_uitest_chromeos.cc
@@ -17,6 +17,7 @@
 #include "base/path_service.h"
 #include "base/run_loop.h"
 #include "chromeos/network/network_handler.h"
+#include "ui/aura/env.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/base/test/ui_controls.h"
 #include "ui/base/ui_base_paths.h"
@@ -69,6 +70,7 @@ class AcceleratorInteractiveUITest : public AshTestBase, public ShellObserver {
         resources_pack_path.Append(FILE_PATH_LITERAL("resources.pak"));
     ResourceBundle::GetSharedInstance().AddDataPackFromPath(
         resources_pack_path, ui::SCALE_FACTOR_NONE);
+    aura::Env::CreateInstance(true);
 
     AshTestBase::SetUp();
 
@@ -83,6 +85,7 @@ class AcceleratorInteractiveUITest : public AshTestBase, public ShellObserver {
     Shell::GetInstance()->RemoveShellObserver(this);
 
     AshTestBase::TearDown();
+    aura::Env::DeleteInstance();
   }
 
   // Sends a key press event and waits synchronously until it's completely
diff --git a/ash/drag_drop/drag_drop_interactive_uitest.cc b/ash/drag_drop/drag_drop_interactive_uitest.cc
index b8968dcd..91d34ac 100644
--- a/ash/drag_drop/drag_drop_interactive_uitest.cc
+++ b/ash/drag_drop/drag_drop_interactive_uitest.cc
@@ -10,6 +10,7 @@
 #include "base/message_loop/message_loop.h"
 #include "base/path_service.h"
 #include "base/strings/utf_string_conversions.h"
+#include "ui/aura/env.h"
 #include "ui/aura/window_event_dispatcher.h"
 #include "ui/base/dragdrop/drag_drop_types.h"
 #include "ui/base/resource/resource_bundle.h"
@@ -134,9 +135,15 @@ class DragDropTest : public test::AshTestBase {
         resources_pack_path.Append(FILE_PATH_LITERAL("resources.pak"));
     ResourceBundle::GetSharedInstance().AddDataPackFromPath(
         resources_pack_path, ui::SCALE_FACTOR_NONE);
+    aura::Env::CreateInstance(true);
 
     test::AshTestBase::SetUp();
   }
+
+  void TearDown() override {
+    test::AshTestBase::TearDown();
+    aura::Env::DeleteInstance();
+  }
 };
 
 #if !defined(OS_CHROMEOS)
diff --git a/ash/shell.cc b/ash/shell.cc
index 4cbc6d4..ef36860 100644
--- a/ash/shell.cc
+++ b/ash/shell.cc
@@ -647,6 +647,7 @@ Shell::Shell(ShellDelegate* delegate)
       simulate_modal_window_open_for_testing_(false),
       is_touch_hud_projection_enabled_(false) {
   DCHECK(delegate_.get());
+  DCHECK(aura::Env::GetInstanceDontCreate());
   gpu_support_.reset(delegate_->CreateGPUSupport());
   display_manager_.reset(new DisplayManager);
   window_tree_host_manager_.reset(new WindowTreeHostManager);
@@ -881,7 +882,6 @@ void Shell::Init(const ShellInitParams& init_params) {
   // Shelf, and WallPaper could be created by the factory.
   views::FocusManagerFactory::Install(new AshFocusManagerFactory);
 
-  aura::Env::CreateInstance(true);
   aura::Env::GetInstance()->set_context_factory(init_params.context_factory);
 
   // The WindowModalityController needs to be at the front of the input event
diff --git a/ash/test/ash_test_helper.cc b/ash/test/ash_test_helper.cc
index 22f16bb..177f3ad 100644
--- a/ash/test/ash_test_helper.cc
+++ b/ash/test/ash_test_helper.cc
@@ -128,7 +128,6 @@ void AshTestHelper::TearDown() {
   }
 #endif
 
-  aura::Env::DeleteInstance();
   ui::TerminateContextFactoryForTests();
 
   // Need to reset the initial login status.
@@ -144,7 +143,6 @@ void AshTestHelper::TearDown() {
 
 void AshTestHelper::RunAllPendingInMessageLoop() {
   DCHECK(base::MessageLoopForUI::current() == message_loop_);
-  aura::Env::CreateInstance(true);
   base::RunLoop run_loop;
   run_loop.RunUntilIdle();
 }
diff --git a/ash/test/test_suite.cc b/ash/test/test_suite.cc
index 73de7b3..c39c76b 100644
--- a/ash/test/test_suite.cc
+++ b/ash/test/test_suite.cc
@@ -9,6 +9,7 @@
 #include "base/files/file_path.h"
 #include "build/build_config.h"
 #include "testing/gtest/include/gtest/gtest.h"
+#include "ui/aura/env.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/base/ui_base_paths.h"
 #include "ui/gfx/gfx_paths.h"
@@ -58,9 +59,11 @@ void AuraShellTestSuite::Initialize() {
       "en-US", NULL, ui::ResourceBundle::LOAD_COMMON_RESOURCES);
 
   base::DiscardableMemoryAllocator::SetInstance(&discardable_memory_allocator_);
+  aura::Env::CreateInstance(true);
 }
 
 void AuraShellTestSuite::Shutdown() {
+  aura::Env::DeleteInstance();
   ui::ResourceBundle::CleanupSharedInstance();
 #if defined(OS_WIN)
   com_initializer_.reset();
diff --git a/ash/wm/ash_native_cursor_manager_interactive_uitest.cc b/ash/wm/ash_native_cursor_manager_interactive_uitest.cc
index a7d0536..214394b 100644
--- a/ash/wm/ash_native_cursor_manager_interactive_uitest.cc
+++ b/ash/wm/ash_native_cursor_manager_interactive_uitest.cc
@@ -10,6 +10,7 @@
 #include "ash/test/cursor_manager_test_api.h"
 #include "base/path_service.h"
 #include "base/run_loop.h"
+#include "ui/aura/env.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_tree_host.h"
 #include "ui/base/resource/resource_bundle.h"
@@ -42,9 +43,15 @@ class AshNativeCursorManagerTest : public test::AshTestBase {
         resources_pack_path.Append(FILE_PATH_LITERAL("resources.pak"));
     ResourceBundle::GetSharedInstance().AddDataPackFromPath(
         resources_pack_path, ui::SCALE_FACTOR_NONE);
+    aura::Env::CreateInstance(true);
 
     test::AshTestBase::SetUp();
   }
+
+  void TearDown() override {
+    test::AshTestBase::TearDown();
+    aura::Env::DeleteInstance();
+  }
 };
 
 namespace {