Small fixes for Mojo docs

Change-Id: I5c9b07a3252a6cc3c303c8da3ccd2252be72d242
Reviewed-on: https://chromium-review.googlesource.com/1158717
Commit-Queue: Tom McKee <tommckee@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#580221}

docs/mojo_guide.md

@@ -15,7 +15,7 @@ that message on the other endpoint. Message pipes are thus bidirectional.
 A **mojom** file describes **interfaces** which describe strongly typed message
 structures, similar to proto files.
 
-Given a **mojom interface** and a **message pipe**, the two **message pipes**
+Given a **mojom interface** and a **message pipe**, the two **endpoints**
 can be given the labels **InterfacePtr** and **Binding**. This now describes a
 strongly typed **message pipe** which transports messages described by the
 **mojom interface**. The **InterfacePtr** is the **endpoint** which "sends"

mojo/public/cpp/bindings/README.md

@@ -669,7 +669,7 @@ For example, consider the following Mojom definitions:
 ```cpp
 union Value {
   int64 int_value;
-  float32 float_value;
+  float float_value;
   string string_value;
 };
 
@@ -678,12 +678,17 @@ interface Dictionary {
 };
 ```
 
-This generates a the following C++ interface:
+This generates the following C++ interface:
 
 ```cpp
 class Value {
  public:
-  virtual ~Value() {}
+  ~Value() {}
+};
+
+class Dictionary {
+ public:
+  virtual ~Dictionary() {}
 
   virtual void AddValue(const std::string& key, ValuePtr value) = 0;
 };