Fix google-explicit-constructor warnings in surfaceflinger.

* Add explicit keyword to conversion constructors,
  or use NOLINT for implicit converters.
Bug: 28341362
Test: build with WITH_TIDY=1

Change-Id: I94f511c3be31dc22022db6466ee9ed0c6be2bc8e
diff --git a/services/surfaceflinger/DisplayHardware/FloatRect.h b/services/surfaceflinger/DisplayHardware/FloatRect.h
index 9ad1040..151eaaa 100644
--- a/services/surfaceflinger/DisplayHardware/FloatRect.h
+++ b/services/surfaceflinger/DisplayHardware/FloatRect.h
@@ -32,7 +32,7 @@
 
     inline FloatRect()
         : left(0), top(0), right(0), bottom(0) { }
-    inline FloatRect(const Rect& other)
+    inline FloatRect(const Rect& other)  // NOLINT(implicit)
         : left(other.left), top(other.top), right(other.right), bottom(other.bottom) { }
 
     inline float getWidth() const { return right - left; }
diff --git a/services/surfaceflinger/DisplayHardware/HWC2.h b/services/surfaceflinger/DisplayHardware/HWC2.h
index 8ab61e9..1aa4205 100644
--- a/services/surfaceflinger/DisplayHardware/HWC2.h
+++ b/services/surfaceflinger/DisplayHardware/HWC2.h
@@ -56,7 +56,7 @@
 class Device
 {
 public:
-    Device(hwc2_device_t* device);
+    explicit Device(hwc2_device_t* device);
     ~Device();
 
     friend class HWC2::Display;
diff --git a/services/surfaceflinger/DisplayHardware/HWC2On1Adapter.h b/services/surfaceflinger/DisplayHardware/HWC2On1Adapter.h
index dc7c355..5debb9a 100644
--- a/services/surfaceflinger/DisplayHardware/HWC2On1Adapter.h
+++ b/services/surfaceflinger/DisplayHardware/HWC2On1Adapter.h
@@ -43,7 +43,7 @@
 class HWC2On1Adapter : public hwc2_device_t
 {
 public:
-    HWC2On1Adapter(struct hwc_composer_device_1* hwc1Device);
+    explicit HWC2On1Adapter(struct hwc_composer_device_1* hwc1Device);
     ~HWC2On1Adapter();
 
     struct hwc_composer_device_1* getHwc1Device() const { return mHwc1Device; }
@@ -488,7 +488,7 @@
 
     class Layer {
         public:
-            Layer(Display& display);
+            explicit Layer(Display& display);
 
             bool operator==(const Layer& other) { return mId == other.mId; }
             bool operator!=(const Layer& other) { return !(*this == other); }