ARC IME: Support CancelComposition.

Applications can request IME to abandon the current composition, for instance
when the app replaced the text content by auto completion.
This CLL adds a Mojo IPC for handling the request and adds Chrome side impl.

BUG=b/26627460

Review URL: https://codereview.chromium.org/1670733003

Cr-Commit-Position: refs/heads/master@{#376879}

7 files changed, 36 insertions, 1 deletions

diff --git a/components/arc/common/ime.mojom b/components/arc/common/ime.mojom
index f5fc86a..6af2b88 100644
--- a/components/arc/common/ime.mojom
+++ b/components/arc/common/ime.mojom
@@ -44,6 +44,9 @@ interface ImeHost {
 
   // Notifies Chrome that the cursor poisition has changed.
   OnCursorRectChanged(CursorRect rect);
+
+  // Notifies Chrome that the current composition is canceled.
+  [MinVersion=1] OnCancelComposition();
 };
 
 interface ImeInstance {
diff --git a/components/arc/ime/arc_ime_bridge.cc b/components/arc/ime/arc_ime_bridge.cc
index ec7ba5e..e129edf 100644
--- a/components/arc/ime/arc_ime_bridge.cc
+++ b/components/arc/ime/arc_ime_bridge.cc
@@ -157,6 +157,12 @@ void ArcImeBridge::OnCursorRectChanged(const gfx::Rect& rect) {
     input_method->OnCaretBoundsChanged(this);
 }
 
+void ArcImeBridge::OnCancelComposition() {
+  ui::InputMethod* const input_method = GetInputMethod();
+  if (input_method)
+    input_method->CancelComposition(this);
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // Oberridden from ui::TextInputClient:
 
diff --git a/components/arc/ime/arc_ime_bridge.h b/components/arc/ime/arc_ime_bridge.h
index 1fcfc1b..561eb44 100644
--- a/components/arc/ime/arc_ime_bridge.h
+++ b/components/arc/ime/arc_ime_bridge.h
@@ -61,6 +61,7 @@ class ArcImeBridge : public ArcService,
   // Overridden from ArcImeIpcHost::Delegate:
   void OnTextInputTypeChanged(ui::TextInputType type) override;
   void OnCursorRectChanged(const gfx::Rect& rect) override;
+  void OnCancelComposition() override;
 
   // Overridden from ui::TextInputClient:
   void SetCompositionText(const ui::CompositionText& composition) override;
diff --git a/components/arc/ime/arc_ime_bridge_unittest.cc b/components/arc/ime/arc_ime_bridge_unittest.cc
index bddb887..7cd1614 100644
--- a/components/arc/ime/arc_ime_bridge_unittest.cc
+++ b/components/arc/ime/arc_ime_bridge_unittest.cc
@@ -29,7 +29,9 @@ class FakeArcImeIpcHost : public ArcImeIpcHost {
 
 class FakeInputMethod : public ui::DummyInputMethod {
  public:
-  FakeInputMethod() : client_(nullptr), count_show_ime_if_needed_(0) {}
+  FakeInputMethod() : client_(nullptr),
+                      count_show_ime_if_needed_(0),
+                      count_cancel_composition_(0) {}
 
   void SetFocusedTextInputClient(ui::TextInputClient* client) override {
     client_ = client;
@@ -43,13 +45,23 @@ class FakeInputMethod : public ui::DummyInputMethod {
     count_show_ime_if_needed_++;
   }
 
+  void CancelComposition(const ui::TextInputClient* client) override {
+    if (client == client_)
+      count_cancel_composition_++;
+  }
+
   int count_show_ime_if_needed() const {
     return count_show_ime_if_needed_;
   }
 
+  int count_cancel_composition() const {
+    return count_cancel_composition_;
+  }
+
  private:
   ui::TextInputClient* client_;
   int count_show_ime_if_needed_;
+  int count_cancel_composition_;
 };
 
 }  // namespace
@@ -126,4 +138,11 @@ TEST_F(ArcImeBridgeTest, ShowImeIfNeeded) {
   EXPECT_EQ(2, fake_input_method_->count_show_ime_if_needed());
 }
 
+TEST_F(ArcImeBridgeTest, CancelComposition) {
+  // The bridge should forward the cancel event to the input method.
+  fake_input_method_->SetFocusedTextInputClient(instance_.get());
+  instance_->OnCancelComposition();
+  EXPECT_EQ(1, fake_input_method_->count_cancel_composition());
+}
+
 }  // namespace arc
diff --git a/components/arc/ime/arc_ime_ipc_host.h b/components/arc/ime/arc_ime_ipc_host.h
index 24ec506..7f5087c 100644
--- a/components/arc/ime/arc_ime_ipc_host.h
+++ b/components/arc/ime/arc_ime_ipc_host.h
@@ -30,6 +30,7 @@ class ArcImeIpcHost {
    public:
     virtual void OnTextInputTypeChanged(ui::TextInputType type) = 0;
     virtual void OnCursorRectChanged(const gfx::Rect& rect) = 0;
+    virtual void OnCancelComposition() = 0;
   };
 
   // Serializes and sends IME related requests through IPCs.
diff --git a/components/arc/ime/arc_ime_ipc_host_impl.cc b/components/arc/ime/arc_ime_ipc_host_impl.cc
index 086fc57..9cee03d 100644
--- a/components/arc/ime/arc_ime_ipc_host_impl.cc
+++ b/components/arc/ime/arc_ime_ipc_host_impl.cc
@@ -127,4 +127,8 @@ void ArcImeIpcHostImpl::OnCursorRectChanged(arc::CursorRectPtr rect) {
       rect->bottom - rect->top));
 }
 
+void ArcImeIpcHostImpl::OnCancelComposition() {
+  delegate_->OnCancelComposition();
+}
+
 }  // namespace arc
diff --git a/components/arc/ime/arc_ime_ipc_host_impl.h b/components/arc/ime/arc_ime_ipc_host_impl.h
index 04bcc6d..643b32c 100644
--- a/components/arc/ime/arc_ime_ipc_host_impl.h
+++ b/components/arc/ime/arc_ime_ipc_host_impl.h
@@ -40,6 +40,7 @@ class ArcImeIpcHostImpl : public ArcImeIpcHost,
   // arc::ImeHost overrides:
   void OnTextInputTypeChanged(arc::TextInputType type) override;
   void OnCursorRectChanged(arc::CursorRectPtr rect) override;
+  void OnCancelComposition() override;
 
  private:
   mojo::Binding<ImeHost> binding_;