Implemented ForceMaximizeBrowserWindowOnFirstRun policy, added unit test and browser test.

ash/wm/window_positioner.cc

Index: ash/wm/window_positioner.cc
diff --git a/ash/wm/window_positioner.cc b/ash/wm/window_positioner.cc
index 4e80ed84a8602a33efee583617fe3fe4f5077df2..db236b91b8ea3771be7306de2e6ee3253083a1ef 100644
--- a/ash/wm/window_positioner.cc
+++ b/ash/wm/window_positioner.cc
@@ -6,6 +6,7 @@
 
 #include "ash/screen_util.h"
 #include "ash/shell.h"
+#include "ash/shell_delegate.h"
 #include "ash/shell_window_ids.h"
 #include "ash/wm/mru_window_tracker.h"
 #include "ash/wm/window_resizer.h"
@@ -246,7 +247,6 @@ void WindowPositioner::GetBoundsAndShowStateForNewWindow(
     ui::WindowShowState show_state_in,
     gfx::Rect* bounds_in_out,
     ui::WindowShowState* show_state_out) {
-
   // Always open new window in the target display.
   aura::Window* target = Shell::GetTargetRootWindow();
 
@@ -264,14 +264,23 @@ void WindowPositioner::GetBoundsAndShowStateForNewWindow(
     // Use adjusted saved bounds, if there is one.
     if (is_saved_bounds)
       return;
-    // When using "small screens" we want to always open in full screen mode.
-    if (show_state_in == ui::SHOW_STATE_DEFAULT && (maximize_first_window ||
-         (work_area.width() <= GetForceMaximizedWidthLimit() &&
-         (!new_window || !wm::GetWindowState(new_window)->IsFullscreen())))) {
+
+    // Policy to maximize window on the first run works only for Chrome OS.

[bartfab (slow), 2015/03/12 11:54:43]

Nit: No need for this comment. Ash is cross-plaform and will honor whatever the
delegate tells it to do. The fact that |true| is only possible on Chrome OS is
irrelevant to ash.

[peletskyi, 2015/03/18 13:28:09]

Done.

+    const bool maximized_first_run =

[bartfab (slow), 2015/03/12 11:54:43]

1: Nit: How about s/maximized_first_run/maximize_first_window_on_first_run/ for
consistency?

[peletskyi, 2015/03/18 13:28:09]

Done.

+        Shell::GetInstance()->delegate()->IsFirstTimeMaximized();
+    // When using "small screens" we want to always open in full screen mode,

[bartfab (slow), 2015/03/12 11:54:43]

Nit: How about "We want to always open maximized on "small screens" or when
policy tells us to?"

[peletskyi, 2015/03/18 13:28:09]

Done.

+    // or when the policy ForceMaximizeBrowserWindowOnFirstRun is set to true.
+    const bool set_maximized =
+        maximize_first_window ||
+        ((work_area.width() <= GetForceMaximizedWidthLimit() ||
+          maximized_first_run) &&

[bartfab (slow), 2015/03/12 11:54:43]

Where is the code that ensures we only enforce this policy for the *first*
window, i.e., we do not enforce it again when all windows are closed and a new
one gets opened?

+         (!new_window || !wm::GetWindowState(new_window)->IsFullscreen()));
+    if (show_state_in == ui::SHOW_STATE_DEFAULT && set_maximized) {

[bartfab (slow), 2015/03/12 11:54:43]

Nit: You should rearrange this so that |set_maximized| is not calculated when it
is not needed:

if (show_state_in == ui::SHOW_STATE_DEFAULT) {
  const bool bool set_maximized = ...;
  if (set_maximized)
    *show_state_out = ui::SHOW_STATE_MAXIMIZED;
}

[peletskyi, 2015/03/18 13:28:09]

Done.

       *show_state_out = ui::SHOW_STATE_MAXIMIZED;
     }
     return;
   }
+
   wm::WindowState* top_window_state = wm::GetWindowState(top_window);
   bool maximized = top_window_state->IsMaximized();
   // We ignore the saved show state, but look instead for the top level