The on screen keyboard on Windows 8+ should not obscure the input field.

content/browser/renderer_host/render_widget_host_view_aura.cc

Index: content/browser/renderer_host/render_widget_host_view_aura.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_aura.cc b/content/browser/renderer_host/render_widget_host_view_aura.cc
index c33e325cef30eaab1a331b7c0dcf7f6d7f8f6166..844da697955017d2910a5be7dfcdf2262ac13d22 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura.cc
+++ b/content/browser/renderer_host/render_widget_host_view_aura.cc
@@ -97,10 +97,13 @@
 #include "ui/wm/public/window_types.h"
 
 #if defined(OS_WIN)
+#include "base/time/time.h"
 #include "content/browser/accessibility/browser_accessibility_manager_win.h"
 #include "content/browser/accessibility/browser_accessibility_win.h"
 #include "content/browser/renderer_host/legacy_render_widget_host_win.h"
 #include "ui/base/win/hidden_window.h"
+#include "ui/base/win/osk_display_manager.h"
+#include "ui/base/win/osk_display_observer.h"
 #include "ui/display/win/screen_win.h"
 #include "ui/gfx/gdi_util.h"
 #endif
@@ -212,6 +215,78 @@ void MarkUnchangedTouchPointsAsStationary(
   }
 }
 
+#if defined(OS_WIN)
+// This class implements the ui::OnScreenKeyboardObserver interface
+// which provides notifications about the on screen keyboard on Windows getting
+// displayed or hidden in response to taps on editable fields.
+// It provides functionality to request blink to scroll the input field if it
+// is obscured by the on screen keyboard.
+class WinScreenKeyboardObserver : public ui::OnScreenKeyboardObserver {
+ public:
+  explicit WinScreenKeyboardObserver(RenderWidgetHostImpl* host,

[grt (UTC plus 2), 2016/05/20 14:56:35]

nit: omit "explicit" as per
https://google.github.io/styleguide/cppguide.html#Implicit_Conversions:
"Constructors that cannot be called with a single argument should usually omit
explicit."

[ananta, 2016/05/20 19:32:54]

Done.

+                                     const gfx::Point& location_dips,
+                                     float scale_factor,
+                                     const gfx::Rect& bounds_in_screen)
+      : host_(host),
+        location_in_dips_(location_dips),
+        device_scale_factor_(scale_factor),
+        bounds_in_screen_(bounds_in_screen) {
+    if (host_ && host_->GetView())
+      host_->GetView()->SetInsets(gfx::Insets());
+  }
+
+  // base::win::OnScreenKeyboardObserver overrides.
+  void OnKeyboardVisible(const gfx::Rect& keyboard_rect_pixels) override {
+    DCHECK(host_);

[grt (UTC plus 2), 2016/05/20 14:56:35]

it's counter to style to both DCHECK that a ptr is not null and check for
nullness at the point of use
(https://groups.google.com/a/chromium.org/d/msg/chromium-dev/ti040zXE_A8/JXfq_...).
can the host ever really be null? if not, remove the check below. otherwise,
remove the DCHECK.

[ananta, 2016/05/20 19:32:55]

Removed the DCHECK

+
+    if (host_ && host_->GetView()) {
+      // We use the PtInRect API to determine if the touch occurred in the
+      // bounds of the OSK.
+      // The API expects the point and the rectangle in pixels.
+      RECT keyboard_rect_windows = keyboard_rect_pixels.ToRECT();
+
+      gfx::Point location_in_pixels =
+          gfx::ConvertPointToPixel(device_scale_factor_, location_in_dips_);
+      POINT touch_location = location_in_pixels.ToPOINT();
+
+      if (::PtInRect(&keyboard_rect_windows, touch_location)) {
+        DVLOG(1) << "OSK covering focus point.";
+        gfx::Rect keyboard_rect_dips =
+            gfx::ConvertRectToDIP(device_scale_factor_, keyboard_rect_pixels);
+        // Get the intersection of the view rectangle and the OSK.
+        // The viewport needs to be moved up by the height of the intersection.
+        gfx::Rect intersect =
+            gfx::IntersectRects(keyboard_rect_dips, bounds_in_screen_);
+        host_->GetView()->SetInsets(gfx::Insets(0, 0, intersect.height(), 0));
+        host_->ScrollFocusedEditableNodeIntoRect(intersect);
+      } else {
+        // Restore the viewport.
+        host_->GetView()->SetInsets(gfx::Insets());
+      }
+    }
+  }
+
+  void OnKeyboardHidden(const gfx::Rect& keyboard_rect_pixels) override {
+    DCHECK(host_);
+    // Restore the viewport.
+    if (host_ && host_->GetView())
+      host_->GetView()->SetInsets(gfx::Insets());
+  }
+
+ private:
+  RenderWidgetHostImpl* host_;
+  // The location in DIPs where the touch occurred.
+  gfx::Point location_in_dips_;
+  // The current device scale factor.
+  float device_scale_factor_;
+
+  // The window bounds in screen coordinates.
+  gfx::Rect bounds_in_screen_;
+
+  DISALLOW_COPY_AND_ASSIGN(WinScreenKeyboardObserver);
+};
+#endif
+
 }  // namespace
 
 // We need to watch for mouse events outside a Web Popup or its parent
@@ -383,6 +458,7 @@ RenderWidgetHostViewAura::RenderWidgetHostViewAura(RenderWidgetHost* host,
 #if defined(OS_WIN)
       legacy_render_widget_host_HWND_(nullptr),
       legacy_window_destroyed_(false),
+      virtual_keyboard_requested_(false),
 #endif
       has_snapped_to_boundary_(false),
       is_guest_view_hack_(is_guest_view_hack),
@@ -864,6 +940,30 @@ void RenderWidgetHostViewAura::SetInsets(const gfx::Insets& insets) {
   }
 }
 
+void RenderWidgetHostViewAura::FocusedNodeTouched(
+    const gfx::Point& location_dips,
+    bool editable) {
+#if defined(OS_WIN)
+  RenderViewHost* rvh = RenderViewHost::From(host_);
+  if (rvh && rvh->GetDelegate())
+    rvh->GetDelegate()->SetIsVirtualKeyboardRequested(editable);
+
+  ui::OnScreenKeyboardDisplayManager* osk_display_manager =
+      ui::OnScreenKeyboardDisplayManager::GetInstance();
+  DCHECK(osk_display_manager);
+  if (editable) {
+    keyboard_observer_.reset(new WinScreenKeyboardObserver(
+        host_, location_dips, device_scale_factor_,
+        window_->GetBoundsInScreen()));
+    virtual_keyboard_requested_ =
+        osk_display_manager->DisplayVirtualKeyboard(keyboard_observer_.get());

[grt (UTC plus 2), 2016/05/20 14:56:34]

looks like this RWHVA could be destroyed while the manager is doing its work,
which would lead the manager holding onto a dangling observer pointer. should
the dtor remove the observer?

[ananta, 2016/05/20 19:32:54]

Done.

+  } else {
+    virtual_keyboard_requested_ = false;
+    osk_display_manager->DismissVirtualKeyboard();
+  }
+#endif
+}
+
 void RenderWidgetHostViewAura::UpdateCursor(const WebCursor& cursor) {
   current_cursor_ = cursor;
   const display::Display display =
@@ -2003,6 +2103,21 @@ void RenderWidgetHostViewAura::TransformPointToLocalCoordSpace(
       gfx::ConvertPointToDIP(device_scale_factor_, *transformed_point);
 }
 
+void RenderWidgetHostViewAura::FocusedNodeChanged(bool editable) {
+#if defined(OS_WIN)
+  if (!editable && virtual_keyboard_requested_) {
+    virtual_keyboard_requested_ = false;
+
+    RenderViewHost* rvh = RenderViewHost::From(host_);
+    if (rvh && rvh->GetDelegate())
+      rvh->GetDelegate()->SetIsVirtualKeyboardRequested(false);
+
+    DCHECK(ui::OnScreenKeyboardDisplayManager::GetInstance());
+    ui::OnScreenKeyboardDisplayManager::GetInstance()->DismissVirtualKeyboard();
+  }
+#endif
+}
+
 void RenderWidgetHostViewAura::OnScrollEvent(ui::ScrollEvent* event) {
   TRACE_EVENT0("input", "RenderWidgetHostViewAura::OnScrollEvent");