Revert 195733 "Enable virtual resolution on low DPI displays"

>Add debug shortcuts that toggles options to shows paint rects, debug borders and fps counters.
>Cleanup: Separate desktop shortcuts which are useful only on linux desktop, and debug shortcuts.
>
>BUG=227375
>Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=195733

TBR=oshima@chromium.org
BUG=

Review URL: https://codereview.chromium.org/14263025

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@195737 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 65 insertions, 121 deletions

diff --git a/ash/display/display_controller_unittest.cc b/ash/display/display_controller_unittest.cc
index 84f615f..c9ecff4 100644
--- a/ash/display/display_controller_unittest.cc
+++ b/ash/display/display_controller_unittest.cc
@@ -319,16 +319,14 @@ TEST_F(DisplayControllerTest, BoundsUpdated) {
   display_manager->SetDisplayRotation(primary_id, gfx::Display::ROTATE_90);
   EXPECT_EQ(0, observer.CountAndReset());
 
-  // UI scale is eanbled only on internal display.
+  // UI scale is eanbled only on internal display (=1st display in unittest).
   int64 secondary_id = GetSecondaryDisplay().id();
   gfx::Display::SetInternalDisplayId(secondary_id);
-  display_manager->SetDisplayUIScale(secondary_id, 1.125f);
-  EXPECT_EQ(1, observer.CountAndReset());
-  display_manager->SetDisplayUIScale(secondary_id, 1.125f);
-  EXPECT_EQ(0, observer.CountAndReset());
-  display_manager->SetDisplayUIScale(primary_id, 1.125f);
+  display_manager->SetDisplayUIScale(secondary_id, 1.25f);
   EXPECT_EQ(0, observer.CountAndReset());
-  display_manager->SetDisplayUIScale(primary_id, 1.125f);
+  display_manager->SetDisplayUIScale(primary_id, 1.25f);
+  EXPECT_EQ(1, observer.CountAndReset());
+  display_manager->SetDisplayUIScale(primary_id, 1.25f);
   EXPECT_EQ(0, observer.CountAndReset());
 }
 
@@ -819,8 +817,6 @@ TEST_F(DisplayControllerTest, MAYBE_ScaleRootWindow) {
   UpdateDisplay("600x400*2@1.5,500x300");
 
   gfx::Display display1 = Shell::GetScreen()->GetPrimaryDisplay();
-  gfx::Display::SetInternalDisplayId(display1.id());
-
   gfx::Display display2 = ScreenAsh::GetSecondaryDisplay();
   Shell::RootWindowList root_windows = Shell::GetAllRootWindows();
   EXPECT_EQ("0,0 450x300", display1.bounds().ToString());
@@ -835,7 +831,7 @@ TEST_F(DisplayControllerTest, MAYBE_ScaleRootWindow) {
 
   internal::DisplayManager* display_manager =
       Shell::GetInstance()->display_manager();
-  display_manager->SetDisplayUIScale(display1.id(), 1.25f);
+  display_manager->SetDisplayUIScale(display1.id(), 1.25);
   display1 = Shell::GetScreen()->GetPrimaryDisplay();
   display2 = ScreenAsh::GetSecondaryDisplay();
   EXPECT_EQ("0,0 375x250", display1.bounds().ToString());
diff --git a/ash/display/display_info.cc b/ash/display/display_info.cc
index fa72bdc..2b8fb54 100644
--- a/ash/display/display_info.cc
+++ b/ash/display/display_info.cc
@@ -148,6 +148,13 @@ void DisplayInfo::Copy(const DisplayInfo& native_info) {
     rotation_ = native_info.rotation_;
     ui_scale_ = native_info.ui_scale_;
   }
+  // It makes little sense to scale beyond the original
+  // resolution. This guard is to protect applying
+  // ui_scale to an external display whose DPI has changed
+  // from 2.0 to 1.0 for some reason.
+  if (ui_scale_ > device_scale_factor_)
+    ui_scale_ = 1.0f;
+
   // Don't copy insets as it may be given by preference.  |rotation_|
   // is treated as a native so that it can be specified in
   // |CreateFromSpec|.
diff --git a/ash/display/display_manager.cc b/ash/display/display_manager.cc
index bb5a148..3e38236 100644
--- a/ash/display/display_manager.cc
+++ b/ash/display/display_manager.cc
@@ -4,7 +4,6 @@
 
 #include "ash/display/display_manager.h"
 
-#include <cmath>
 #include <set>
 #include <string>
 #include <vector>
@@ -56,13 +55,11 @@ typedef std::vector<DisplayInfo> DisplayInfoList;
 
 namespace {
 
-// List of value UI Scale values. Scales for 2x are equivalent to 640,
-// 800, 1024, 1280, 1440, 1600 and 1920 pixel width respectively on
-// 2560 pixel width 2x density display. Please see crbug.com/233375
-// for the full list of resolutions.
-const float kUIScalesFor2x[] = {0.5f, 0.625f, 0.8f, 1.0f, 1.125f, 1.25f, 1.5f};
-const float kUIScalesFor1280[] = {0.5f, 0.625f, 0.8f, 1.0f, 1.125f };
-const float kUIScalesFor1366[] = {0.5f, 0.6f, 0.75f, 1.0f, 1.125f };
+// List of value UI Scale values. These scales are equivalent to 640, 800, 1024,
+// 1280, 1440, 1600 and 1920 pixel width respectively on 2560 pixel width 2x
+// density display.
+const float kUIScales[] = {0.5f, 0.625f, 0.8f, 1.0f, 1.125f, 1.25f, 1.5f};
+const size_t kUIScaleTableSize = arraysize(kUIScales);
 
 struct DisplaySortFunctor {
   bool operator()(const gfx::Display& a, const gfx::Display& b) {
@@ -76,47 +73,19 @@ struct DisplayInfoSortFunctor {
   }
 };
 
-struct ScaleComparator {
-  ScaleComparator(float s) : scale(s) {}
-
-  bool operator()(float s) const {
-    const float kEpsilon = 0.0001f;
-    return std::abs(scale - s) < kEpsilon;
-  }
-  float scale;
-};
-
-std::vector<float> GetScalesForDisplay(const DisplayInfo& info) {
-  std::vector<float> ret;
-  if (info.device_scale_factor() == 2.0f) {
-    ret.assign(kUIScalesFor2x, kUIScalesFor2x + arraysize(kUIScalesFor2x));
-    return ret;
-  }
-  switch (info.bounds_in_pixel().width()) {
-    case 1280:
-      ret.assign(kUIScalesFor1280,
-                 kUIScalesFor1280 + arraysize(kUIScalesFor1280));
-      break;
-    case 1366:
-      ret.assign(kUIScalesFor1366,
-                 kUIScalesFor1366 + arraysize(kUIScalesFor1366));
-      break;
-    default:
-      ret.assign(kUIScalesFor1280,
-                 kUIScalesFor1280 + arraysize(kUIScalesFor1280));
-#if defined(OS_CHROMEOS)
-      if (base::chromeos::IsRunningOnChromeOS())
-        NOTREACHED() << "Unknown resolution:" << info.ToString();
-#endif
-  }
-  return ret;
-}
-
 gfx::Display& GetInvalidDisplay() {
   static gfx::Display* invalid_display = new gfx::Display();
   return *invalid_display;
 }
 
+bool IsValidUIScale(float scale) {
+  for (size_t i = 0; i < kUIScaleTableSize; ++i) {
+    if (kUIScales[i] == scale)
+      return true;
+  }
+  return false;
+}
+
 }  // namespace
 
 using aura::RootWindow;
@@ -153,16 +122,14 @@ void DisplayManager::ToggleDisplayScaleFactor() {
 }
 
 // static
-float DisplayManager::GetNextUIScale(const DisplayInfo& info, bool up) {
-  float scale = info.ui_scale();
-  std::vector<float> scales = GetScalesForDisplay(info);
-  for (size_t i = 0; i < scales.size(); ++i) {
-    if (ScaleComparator(scales[i])(scale)) {
-      if (up && i != scales.size() - 1)
-        return scales[i + 1];
+float DisplayManager::GetNextUIScale(float scale, bool up) {
+  for (size_t i = 0; i < kUIScaleTableSize; ++i) {
+    if (kUIScales[i] == scale) {
+      if (up && i != kUIScaleTableSize -1)
+        return kUIScales[i + 1];
       if (!up && i != 0)
-        return scales[i - 1];
-      return scales[i];
+        return kUIScales[i - 1];
+      return kUIScales[i];
     }
   }
   // Fallback to 1.0f if the |scale| wasn't in the list.
@@ -254,10 +221,8 @@ void DisplayManager::SetDisplayRotation(int64 display_id,
 
 void DisplayManager::SetDisplayUIScale(int64 display_id,
                                        float ui_scale) {
-  if (!IsDisplayUIScalingEnabled() ||
-      gfx::Display::InternalDisplayId() != display_id) {
+  if (!IsDisplayUIScalingEnabled() || !IsValidUIScale(ui_scale))
     return;
-  }
 
   DisplayInfoList display_info_list;
   for (DisplayList::const_iterator iter = displays_.begin();
@@ -266,12 +231,6 @@ void DisplayManager::SetDisplayUIScale(int64 display_id,
     if (info.id() == display_id) {
       if (info.ui_scale() == ui_scale)
         return;
-      std::vector<float> scales = GetScalesForDisplay(info);
-      ScaleComparator comparator(ui_scale);
-      if (std::find_if(scales.begin(), scales.end(), comparator) ==
-          scales.end()) {
-        return;
-      }
       info.set_ui_scale(ui_scale);
     }
     display_info_list.push_back(info);
@@ -290,8 +249,7 @@ void DisplayManager::RegisterDisplayProperty(
   }
 
   display_info_[display_id].set_rotation(rotation);
-  // Just in case the preference file was corrupted.
-  if (0.5f <= ui_scale && ui_scale <= 2.0f)
+  if (IsValidUIScale(ui_scale))
     display_info_[display_id].set_ui_scale(ui_scale);
   if (overscan_insets)
     display_info_[display_id].SetOverscanInsets(true, *overscan_insets);
@@ -628,10 +586,15 @@ void DisplayManager::OnRootWindowResized(const aura::RootWindow* root,
 int64 DisplayManager::GetDisplayIdForUIScaling() const {
   // UI Scaling is effective only on internal display.
   int64 display_id = gfx::Display::InternalDisplayId();
-#if defined(OS_WIN)
+#if defined(OS_CHROMEOS)
+  // On linux desktop, allow ui scalacing on the first dislpay.
+  if (!base::chromeos::IsRunningOnChromeOS())
+    display_id = first_display_id();
+#elif defined(OS_WIN)
   display_id = first_display_id();
 #endif
-  return display_id;
+  return GetDisplayForId(display_id).device_scale_factor() == 2.0f ?
+      display_id : gfx::Display::kInvalidDisplayID;
 }
 
 void DisplayManager::Init() {
@@ -647,9 +610,6 @@ void DisplayManager::Init() {
   if (displays_.empty())
     AddDisplayFromSpec(std::string() /* default */);
   first_display_id_ = displays_[0].id();
-  CommandLine* command_line = CommandLine::ForCurrentProcess();
-  if (command_line->HasSwitch(switches::kAshUseFirstDisplayAsInternal))
-    gfx::Display::SetInternalDisplayId(first_display_id_);
   num_connected_displays_ = displays_.size();
 }
 
@@ -721,6 +681,21 @@ void DisplayManager::InsertAndUpdateDisplayInfo(const DisplayInfo& new_info) {
     display_info_[new_info.id()] = new_info;
     display_info_[new_info.id()].set_native(false);
   }
+  bool on_chromeos = false;
+#if defined(OS_CHROMEOS)
+  on_chromeos = base::chromeos::IsRunningOnChromeOS();
+#endif
+  CommandLine* command_line = CommandLine::ForCurrentProcess();
+  if ((new_info.id() == gfx::Display::InternalDisplayId() || !on_chromeos) &&
+      command_line->HasSwitch(switches::kAshInternalDisplayUIScale)) {
+    double scale_in_double = 1.0;
+    std::string value = CommandLine::ForCurrentProcess()->
+        GetSwitchValueASCII(switches::kAshInternalDisplayUIScale);
+    if (!base::StringToDouble(value, &scale_in_double))
+      LOG(ERROR) << "Failed to parse the display scale:" << value;
+    display_info_[new_info.id()].set_ui_scale(scale_in_double);
+  }
+
   display_info_[new_info.id()].UpdateDisplaySize();
 }
 
diff --git a/ash/display/display_manager.h b/ash/display/display_manager.h
index ffd4e18..b63aec4 100644
--- a/ash/display/display_manager.h
+++ b/ash/display/display_manager.h
@@ -45,7 +45,7 @@ class ASH_EXPORT DisplayManager : public aura::RootWindowObserver {
   static void ToggleDisplayScaleFactor();
 
   // Returns next valid UI scale.
-  static float GetNextUIScale(const DisplayInfo& info, bool up);
+  static float GetNextUIScale(float scale, bool up);
 
   // When set to true, the MonitorManager calls OnDisplayBoundsChanged
   // even if the display's bounds didn't change. Used to swap primary
diff --git a/ash/display/display_manager_unittest.cc b/ash/display/display_manager_unittest.cc
index 66ad123..7ddb8a5 100644
--- a/ash/display/display_manager_unittest.cc
+++ b/ash/display/display_manager_unittest.cc
@@ -714,55 +714,25 @@ TEST_F(DisplayManagerTest, Rotate) {
 }
 
 TEST_F(DisplayManagerTest, UIScale) {
-  UpdateDisplay("1280x800");
+  // 1x display does not support scaling.
+  UpdateDisplay("100x200");
   int64 display_id = Shell::GetScreen()->GetPrimaryDisplay().id();
-  display_manager()->SetDisplayUIScale(display_id, 1.125f);
-  EXPECT_EQ(1.0, GetDisplayInfoAt(0).ui_scale());
-  display_manager()->SetDisplayUIScale(display_id, 0.8f);
-  EXPECT_EQ(1.0f, GetDisplayInfoAt(0).ui_scale());
-  display_manager()->SetDisplayUIScale(display_id, 0.75f);
-  EXPECT_EQ(1.0f, GetDisplayInfoAt(0).ui_scale());
-  display_manager()->SetDisplayUIScale(display_id, 0.625f);
-  EXPECT_EQ(1.0f, GetDisplayInfoAt(0).ui_scale());
-
-  gfx::Display::SetInternalDisplayId(display_id);
 
   display_manager()->SetDisplayUIScale(display_id, 1.5f);
   EXPECT_EQ(1.0f, GetDisplayInfoAt(0).ui_scale());
   display_manager()->SetDisplayUIScale(display_id, 1.25f);
   EXPECT_EQ(1.0f, GetDisplayInfoAt(0).ui_scale());
   display_manager()->SetDisplayUIScale(display_id, 1.125f);
-  EXPECT_EQ(1.125f, GetDisplayInfoAt(0).ui_scale());
+  EXPECT_EQ(1.0, GetDisplayInfoAt(0).ui_scale());
   display_manager()->SetDisplayUIScale(display_id, 0.8f);
-  EXPECT_EQ(0.8f, GetDisplayInfoAt(0).ui_scale());
-  display_manager()->SetDisplayUIScale(display_id, 0.75f);
-  EXPECT_EQ(0.8f, GetDisplayInfoAt(0).ui_scale());
-  display_manager()->SetDisplayUIScale(display_id, 0.625f);
-  EXPECT_EQ(0.625f, GetDisplayInfoAt(0).ui_scale());
-  display_manager()->SetDisplayUIScale(display_id, 0.6f);
-  EXPECT_EQ(0.625f, GetDisplayInfoAt(0).ui_scale());
-  display_manager()->SetDisplayUIScale(display_id, 0.5f);
-  EXPECT_EQ(0.5f, GetDisplayInfoAt(0).ui_scale());
-
-  UpdateDisplay("1366x768");
-  display_manager()->SetDisplayUIScale(display_id, 1.5f);
   EXPECT_EQ(1.0f, GetDisplayInfoAt(0).ui_scale());
-  display_manager()->SetDisplayUIScale(display_id, 1.25f);
-  EXPECT_EQ(1.0f, GetDisplayInfoAt(0).ui_scale());
-  display_manager()->SetDisplayUIScale(display_id, 1.125f);
-  EXPECT_EQ(1.125f, GetDisplayInfoAt(0).ui_scale());
-  display_manager()->SetDisplayUIScale(display_id, 0.8f);
-  EXPECT_EQ(1.125f, GetDisplayInfoAt(0).ui_scale());
-  display_manager()->SetDisplayUIScale(display_id, 0.75f);
-  EXPECT_EQ(0.75f, GetDisplayInfoAt(0).ui_scale());
-  display_manager()->SetDisplayUIScale(display_id, 0.6f);
-  EXPECT_EQ(0.6f, GetDisplayInfoAt(0).ui_scale());
   display_manager()->SetDisplayUIScale(display_id, 0.625f);
-  EXPECT_EQ(0.6f, GetDisplayInfoAt(0).ui_scale());
+  EXPECT_EQ(1.0f, GetDisplayInfoAt(0).ui_scale());
   display_manager()->SetDisplayUIScale(display_id, 0.5f);
-  EXPECT_EQ(0.5f, GetDisplayInfoAt(0).ui_scale());
+  EXPECT_EQ(1.0f, GetDisplayInfoAt(0).ui_scale());
 
-  UpdateDisplay("1280x850*2");
+  // 2x display supports all scales.
+  UpdateDisplay("100x200*2");
   EXPECT_EQ(1.0f, GetDisplayInfoAt(0).ui_scale());
   display_manager()->SetDisplayUIScale(display_id, 1.5f);
   EXPECT_EQ(1.5f, GetDisplayInfoAt(0).ui_scale());
@@ -772,12 +742,8 @@ TEST_F(DisplayManagerTest, UIScale) {
   EXPECT_EQ(1.125f, GetDisplayInfoAt(0).ui_scale());
   display_manager()->SetDisplayUIScale(display_id, 0.8f);
   EXPECT_EQ(0.8f, GetDisplayInfoAt(0).ui_scale());
-  display_manager()->SetDisplayUIScale(display_id, 0.75f);
-  EXPECT_EQ(0.8f, GetDisplayInfoAt(0).ui_scale());
   display_manager()->SetDisplayUIScale(display_id, 0.625f);
   EXPECT_EQ(0.625f, GetDisplayInfoAt(0).ui_scale());
-  display_manager()->SetDisplayUIScale(display_id, 0.6f);
-  EXPECT_EQ(0.625f, GetDisplayInfoAt(0).ui_scale());
   display_manager()->SetDisplayUIScale(display_id, 0.5f);
   EXPECT_EQ(0.5f, GetDisplayInfoAt(0).ui_scale());
 }