[reland] Browser Side Text Input State Tracking for OOPIF (Aura Only)

content/browser/renderer_host/render_widget_host_view_base.cc

Index: content/browser/renderer_host/render_widget_host_view_base.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_base.cc b/content/browser/renderer_host/render_widget_host_view_base.cc
index dd88faea8fae27b0cfc71207869e299227a5a363..969aee2aeaf7b54115efd8a775176492485acc95 100644
--- a/content/browser/renderer_host/render_widget_host_view_base.cc
+++ b/content/browser/renderer_host/render_widget_host_view_base.cc
@@ -13,6 +13,7 @@
 #include "content/browser/renderer_host/render_widget_host_delegate.h"
 #include "content/browser/renderer_host/render_widget_host_impl.h"
 #include "content/browser/renderer_host/render_widget_host_view_base_observer.h"
+#include "content/browser/renderer_host/text_input_manager.h"
 #include "content/common/content_switches_internal.h"
 #include "content/public/browser/render_widget_host_view_frame_subscriber.h"
 #include "ui/display/display.h"
@@ -40,6 +41,7 @@ RenderWidgetHostViewBase::RenderWidgetHostViewBase()
       current_device_scale_factor_(0),
       current_display_rotation_(display::Display::ROTATE_0),
       pinch_zoom_enabled_(content::IsPinchToZoomEnabled()),
+      text_input_manager_(nullptr),
       renderer_frame_number_(0),
       weak_factory_(this) {}
 
@@ -53,6 +55,10 @@ RenderWidgetHostViewBase::~RenderWidgetHostViewBase() {
   // NotifyObserversAboutShutdown() twice, as the observers are required to
   // de-register on the first call, and so the second call does nothing.
   NotifyObserversAboutShutdown();
+  // If we have a live reference to |text_input_manager_|, we should unregister
+  // so that the |text_input_manager_| will free its state.
+  if (text_input_manager_)
+    text_input_manager_->Unregister(this);
 }
 
 void RenderWidgetHostViewBase::NotifyObserversAboutShutdown() {
@@ -228,6 +234,13 @@ bool RenderWidgetHostViewBase::HasDisplayPropertyChanged(gfx::NativeView view) {
   return true;
 }
 
+void RenderWidgetHostViewBase::DidUnregisterFromTextInputManager(
+    TextInputManager* text_input_manager) {
+  DCHECK(text_input_manager && text_input_manager_ == text_input_manager);
+
+  text_input_manager_ = nullptr;
+}
+
 base::WeakPtr<RenderWidgetHostViewBase> RenderWidgetHostViewBase::GetWeakPtr() {
   return weak_factory_.GetWeakPtr();
 }
@@ -382,6 +395,34 @@ void RenderWidgetHostViewBase::TransformPointToLocalCoordSpace(
   *transformed_point = point;
 }
 
+void RenderWidgetHostViewBase::TextInputStateChanged(
+    const TextInputState& text_input_state) {
+// TODO(ekaramad): Use TextInputManager code paths when IME is implemented on
+// other platforms.
+#if defined(USE_AURA)
+  if (GetTextInputManager())
+    GetTextInputManager()->UpdateTextInputState(this, text_input_state);
+#endif
+}
+
+TextInputManager* RenderWidgetHostViewBase::GetTextInputManager() {
+  if (text_input_manager_)
+    return text_input_manager_;
+
+  RenderWidgetHostImpl* host =
+      RenderWidgetHostImpl::From(GetRenderWidgetHost());
+  if (!host || !host->delegate())
+    return nullptr;
+
+  // This RWHV needs to be registered with the TextInputManager so that the
+  // TextInputManager starts tracking its state, and observing its lifetime.
+  text_input_manager_ = host->delegate()->GetTextInputManager();

[Charlie Reis, 2016/05/26 06:22:04]

Is there a reason we do this lazily, rather than when the RWHV is constructed?

[EhsanK, 2016/05/30 15:06:08]

I do not see any critical reasons against proper initialization. We do this for
tab's RWHV; but it is necessary for tab's RWHV since it must observe
TextInputManager as soon as and as long as it can.

The reason for lazy initialization was that a RWHV might not even have any
<input> inside it. Then why bother with tracking  IME when it can not even have
it.

+  if (text_input_manager_)
+    text_input_manager_->Register(this);
+
+  return text_input_manager_;
+}
+
 void RenderWidgetHostViewBase::AddObserver(
     RenderWidgetHostViewBaseObserver* observer) {
   observers_.AddObserver(observer);