Revert "Speculative revert by sheriff"

This reverts commit 919dce4400651813d5ff6e8a85b944a5987adcb7.

BUG=None
TBR=akuegel

Review URL: https://codereview.chromium.org/1094553002

Cr-Commit-Position: refs/heads/master@{#325412}

2 files changed, 31 insertions, 10 deletions

diff --git a/ash/content/display/screen_orientation_controller_chromeos.cc b/ash/content/display/screen_orientation_controller_chromeos.cc
index 07659d7c..dbd4465 100644
--- a/ash/content/display/screen_orientation_controller_chromeos.cc
+++ b/ash/content/display/screen_orientation_controller_chromeos.cc
@@ -196,10 +196,11 @@ void ScreenOrientationController::Unlock(content::WebContents* web_contents) {
 void ScreenOrientationController::OnDisplayConfigurationChanged() {
   if (ignore_display_configuration_updates_)
     return;
+  DisplayManager* display_manager = Shell::GetInstance()->display_manager();
+  if (!display_manager->HasInternalDisplay())
+    return;
   gfx::Display::Rotation user_rotation =
-      Shell::GetInstance()
-          ->display_manager()
-          ->GetDisplayInfo(gfx::Display::InternalDisplayId())
+      display_manager->GetDisplayInfo(gfx::Display::InternalDisplayId())
           .rotation();
   if (user_rotation != current_rotation_) {
     // A user may change other display configuration settings. When the user
@@ -212,11 +213,14 @@ void ScreenOrientationController::OnDisplayConfigurationChanged() {
 
 void ScreenOrientationController::OnMaximizeModeStarted() {
   DisplayManager* display_manager = Shell::GetInstance()->display_manager();
-  if (!display_manager->HasInternalDisplay())
-    return;
-  current_rotation_ = user_rotation_ =
-      display_manager->GetDisplayInfo(gfx::Display::InternalDisplayId())
-          .rotation();
+  // Do not exit early, as the internal display can be determined after Maximize
+  // Mode has started. (chrome-os-partner:38796)
+  // Always start observing.
+  if (display_manager->HasInternalDisplay()) {
+    current_rotation_ = user_rotation_ =
+        display_manager->GetDisplayInfo(gfx::Display::InternalDisplayId())
+            .rotation();
+  }
   if (!rotation_locked_)
     LoadDisplayRotationProperties();
   chromeos::AccelerometerReader::GetInstance()->AddObserver(this);
@@ -224,8 +228,6 @@ void ScreenOrientationController::OnMaximizeModeStarted() {
 }
 
 void ScreenOrientationController::OnMaximizeModeEnded() {
-  if (!Shell::GetInstance()->display_manager()->HasInternalDisplay())
-    return;
   chromeos::AccelerometerReader::GetInstance()->RemoveObserver(this);
   Shell::GetInstance()->display_controller()->RemoveObserver(this);
   if (current_rotation_ != user_rotation_)
diff --git a/ash/content/display/screen_orientation_controller_chromeos_unittest.cc b/ash/content/display/screen_orientation_controller_chromeos_unittest.cc
index ca02ca3..342e958 100644
--- a/ash/content/display/screen_orientation_controller_chromeos_unittest.cc
+++ b/ash/content/display/screen_orientation_controller_chromeos_unittest.cc
@@ -589,4 +589,23 @@ TEST_F(ScreenOrientationControllerTest, UserRotationLockDisallowsRotation) {
   EXPECT_EQ(gfx::Display::ROTATE_0, GetInternalDisplayRotation());
 }
 
+// Tests that when MaximizeMode is triggered before the internal display is
+// ready, that ScreenOrientationController still begins listening to events,
+// which require an internal display to be acted upon.
+TEST_F(ScreenOrientationControllerTest, InternalDisplayNotAvailableAtStartup) {
+  int64 internal_display_id = gfx::Display::InternalDisplayId();
+  gfx::Display::SetInternalDisplayId(gfx::Display::kInvalidDisplayID);
+
+  EnableMaximizeMode(true);
+
+  // Should not crash, even thought there is no internal display.
+  SetInternalDisplayRotation(gfx::Display::ROTATE_180);
+  EXPECT_FALSE(RotationLocked());
+
+  // With an internal display now available, functionality should resume.
+  gfx::Display::SetInternalDisplayId(internal_display_id);
+  SetInternalDisplayRotation(gfx::Display::ROTATE_90);
+  EXPECT_TRUE(RotationLocked());
+}
+
 }  // namespace ash